diff --git a/src/ArrayList.php b/src/ArrayList.php
index fe03e5a..235fcff 100644
--- a/src/ArrayList.php
+++ b/src/ArrayList.php
@@ -127,6 +127,7 @@ public function set(int $index, mixed $value): void
 			throw new OffsetNotFoundException($index);
 		}
 
+		/** @psalm-suppress ImpureMethodCall */
 		return $this->list[$index];
 	}
 
@@ -148,7 +149,7 @@ public function addAll(iterable $values): void
 		}
 	}
 
-	#[Pure] public function first(?callable $filter = null): mixed
+	public function first(?callable $filter = null): mixed
 	{
 		foreach ($this->list as $item) {
 			if ($filter === null || $filter($item)) {
@@ -163,7 +164,7 @@ public function addAll(iterable $values): void
 	 * @param callable(T): bool $filter
 	 * @return ArrayList<T>
 	 */
-	#[Pure] public function where(callable $filter): ArrayList
+	public function where(callable $filter): ArrayList
 	{
 		$result = new ArrayList();
 
@@ -196,13 +197,12 @@ public function addAll(iterable $values): void
 	 * @param callable(T): TOut $callback
 	 * @return ArrayList<TOut>
 	 */
-	#[Pure] public function map(callable $callback): ArrayList
+	public function map(callable $callback): ArrayList
 	{
 		$arr = new ArrayList();
 
 		foreach ($this->list as $value) {
 			/**
-			 * @psalm-suppress ImpureMethodCall
 			 * @psalm-suppress InvalidArgument Until vimeo/psalm#6821 is fixed
 			 */
 			$arr->add($callback($value));
@@ -211,7 +211,7 @@ public function addAll(iterable $values): void
 		return $arr;
 	}
 
-	#[Pure] public function any(?callable $filter = null): bool
+	public function any(?callable $filter = null): bool
 	{
 		return !$this->isEmpty() && $this->first($filter) !== null;
 	}
@@ -275,7 +275,7 @@ public function unshift(mixed $value): void
 		array_unshift($this->list, $value);
 	}
 
-	#[Pure] public function contains(mixed $value): bool
+	public function contains(mixed $value): bool
 	{
 		return $this->any(static fn($item) => $item === $value);
 	}
@@ -292,7 +292,7 @@ public function orderBy(callable $callback): ArrayList
 		return $this;
 	}
 
-	#[Pure] public function join(Stringable|string $separator): string
+	public function join(Stringable|string $separator): string
 	{
 		return implode((string)$separator, $this->map(fn($item) => (string)$item)->asArray());
 	}
diff --git a/src/ArrayMap.php b/src/ArrayMap.php
index 43a9b77..cd83afd 100644
--- a/src/ArrayMap.php
+++ b/src/ArrayMap.php
@@ -90,7 +90,7 @@ public function put(mixed $key, mixed $value): void
 		return $this->values[$key];
 	}
 
-	#[Pure] public function first(?callable $filter = null): mixed
+	public function first(?callable $filter = null): mixed
 	{
 		foreach ($this->values as $key => $value) {
 			if ($filter === null || $filter($value, $key)) {
@@ -101,7 +101,7 @@ public function put(mixed $key, mixed $value): void
 		return null;
 	}
 
-	#[Pure] public function firstKey(?callable $filter = null): mixed
+	public function firstKey(?callable $filter = null): mixed
 	{
 		foreach ($this->values as $key => $value) {
 			if ($filter === null || $filter($key, $value)) {
@@ -117,7 +117,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TValue, TKey): bool $filter
 	 * @return ArrayMap<TKey, TValue>
 	 */
-	#[Pure] public function where(callable $filter): ArrayMap
+	public function where(callable $filter): ArrayMap
 	{
 		$result = new ArrayMap();
 
@@ -135,7 +135,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TKey, TValue): bool $filter
 	 * @return ArrayMap<TKey, TValue>
 	 */
-	#[Pure] public function whereKey(callable $filter): ArrayMap
+	public function whereKey(callable $filter): ArrayMap
 	{
 		$result = new ArrayMap();
 
@@ -160,7 +160,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TValue, TKey): TOut $callback
 	 * @return ArrayMap<TKey, TOut>
 	 */
-	#[Pure] public function map(callable $callback): ArrayMap
+	public function map(callable $callback): ArrayMap
 	{
 		$map = new ArrayMap();
 
@@ -175,12 +175,12 @@ public function put(mixed $key, mixed $value): void
 		return $map;
 	}
 
-	#[Pure] public function any(?callable $filter = null): bool
+	public function any(?callable $filter = null): bool
 	{
 		return $this->first($filter) !== null;
 	}
 
-	#[Pure] public function anyKey(?callable $filter = null): bool
+	public function anyKey(?callable $filter = null): bool
 	{
 		return $this->firstKey($filter) !== null;
 	}
@@ -201,7 +201,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TValue, TKey): TOut $callback
 	 * @return ArrayList<TOut>
 	 */
-	#[Pure] public function reduce(callable $callback): ArrayList
+	public function reduce(callable $callback): ArrayList
 	{
 		/** @var ArrayList<TOut> $list */
 		$list = new ArrayList();
@@ -219,7 +219,7 @@ public function asArray(): array
 		return $this->values;
 	}
 
-	#[Pure] public function contains(mixed $value): bool
+	public function contains(mixed $value): bool
 	{
 		return $this->any(static fn($item) => $item === $value);
 	}
@@ -243,14 +243,13 @@ public function toJson(int $flags = 0): string
 	 * @param callable(TKey, TValue): TKeyOut $callback
 	 * @return ArrayMap<TKeyOut, TValue>
 	 */
-	#[Pure] public function mapKeys(callable $callback): ArrayMap
+	public function mapKeys(callable $callback): ArrayMap
 	{
 		/** @var ArrayMap<TKeyOut, TValue> $map */
 		$map = new ArrayMap();
 
 		foreach ($this->values as $key => $value) {
 			/**
-			 * @psalm-suppress ImpureMethodCall
 			 * @psalm-suppress InvalidArgument Until vimeo/psalm#6821 is fixed
 			 */
 			$map->put($callback($key, $value), $value);
diff --git a/src/Contract/Filterable.php b/src/Contract/Filterable.php
index d73636e..7b3148d 100644
--- a/src/Contract/Filterable.php
+++ b/src/Contract/Filterable.php
@@ -3,8 +3,6 @@
 
 namespace Elephox\Collection\Contract;
 
-use JetBrains\PhpStorm\Pure;
-
 /**
  * @template T
  */
@@ -14,23 +12,23 @@ interface Filterable
 	 * @param null|callable(T): bool $filter
 	 * @return T|null
 	 */
-	#[Pure] public function first(?callable $filter = null): mixed;
+	public function first(?callable $filter = null): mixed;
 
 	/**
 	 * @param null|callable(T): bool $filter
 	 * @return bool
 	 */
-	#[Pure] public function any(?callable $filter = null): bool;
+	public function any(?callable $filter = null): bool;
 
 	/**
 	 * @param callable(T): bool $filter
 	 * @return GenericCollection<T>
 	 */
-	#[Pure] public function where(callable $filter): GenericCollection;
+	public function where(callable $filter): GenericCollection;
 
 	/**
 	 * @param T $value
 	 * @return bool
 	 */
-	#[Pure] public function contains(mixed $value): bool;
+	public function contains(mixed $value): bool;
 }
diff --git a/src/Contract/GenericCollection.php b/src/Contract/GenericCollection.php
index 0606bfa..0401c4b 100644
--- a/src/Contract/GenericCollection.php
+++ b/src/Contract/GenericCollection.php
@@ -11,6 +11,6 @@
  * @extends Filterable<T>
  * @extends Mappable<T>
  */
-interface GenericCollection extends Filterable, Mappable, DeepCloneable
+interface GenericCollection extends DeepCloneable
 {
 }
diff --git a/src/Contract/ReadonlyList.php b/src/Contract/ReadonlyList.php
index e60e066..785d497 100644
--- a/src/Contract/ReadonlyList.php
+++ b/src/Contract/ReadonlyList.php
@@ -18,7 +18,7 @@
  * @extends iterable<T>
  * @extends list<T>
  */
-interface ReadonlyList extends GenericCollection, Countable, IteratorAggregate, ArrayConvertible
+interface ReadonlyList extends GenericCollection, Filterable, Mappable, Countable, IteratorAggregate, ArrayConvertible
 {
 	/**
 	 * @return T
@@ -29,7 +29,7 @@ interface ReadonlyList extends GenericCollection, Countable, IteratorAggregate,
 	 * @param callable(T): bool $filter
 	 * @return GenericList<T>
 	 */
-	#[Pure] public function where(callable $filter): GenericList;
+	public function where(callable $filter): GenericList;
 
 	/**
 	 * @template TOut
@@ -37,11 +37,11 @@ interface ReadonlyList extends GenericCollection, Countable, IteratorAggregate,
 	 * @param callable(T): TOut $callback
 	 * @return GenericList<TOut>
 	 */
-	#[Pure] public function map(callable $callback): GenericList;
+	public function map(callable $callback): GenericList;
 
 	#[Pure] public function isEmpty(): bool;
 
-	#[Pure] public function join(string|Stringable $separator): string;
+	public function join(string|Stringable $separator): string;
 
 	/**
 	 * @return list<T> Returns this object in its array representation.
diff --git a/src/Contract/ReadonlyMap.php b/src/Contract/ReadonlyMap.php
index d9d1183..7e2b818 100644
--- a/src/Contract/ReadonlyMap.php
+++ b/src/Contract/ReadonlyMap.php
@@ -13,31 +13,31 @@
  * @extends GenericCollection<TValue>
  * @extends IteratorAggregate<TKey, TValue>
  */
-interface ReadonlyMap extends GenericCollection, IteratorAggregate
+interface ReadonlyMap extends GenericCollection, Filterable, Mappable, IteratorAggregate
 {
 	/**
 	 * @param TKey $key
 	 * @return TValue
 	 */
-	#[Pure] public function get(mixed $key): mixed;
+	public function get(mixed $key): mixed;
 
 	/**
 	 * @param TKey $key
 	 */
-	#[Pure] public function has(mixed $key): bool;
+	public function has(mixed $key): bool;
 
 	/**
 	 * @param callable(TValue, TKey): bool $filter
 	 * @return GenericMap<TKey, TValue>
 	 */
-	#[Pure] public function where(callable $filter): GenericMap;
+	public function where(callable $filter): GenericMap;
 
 
 	/**
 	 * @param callable(TKey, TValue): bool $filter
 	 * @return GenericMap<TKey, TValue>
 	 */
-	#[Pure] public function whereKey(callable $filter): GenericMap;
+	public function whereKey(callable $filter): GenericMap;
 
 	/**
 	 * @template TOut
@@ -45,7 +45,7 @@ interface ReadonlyMap extends GenericCollection, IteratorAggregate
 	 * @param callable(TValue, TKey): TOut $callback
 	 * @return GenericMap<TKey, TOut>
 	 */
-	#[Pure] public function map(callable $callback): GenericMap;
+	public function map(callable $callback): GenericMap;
 
 	/**
 	 * @template TKeyOut
@@ -53,7 +53,7 @@ interface ReadonlyMap extends GenericCollection, IteratorAggregate
 	 * @param callable(TKey, TValue): TKeyOut $callback
 	 * @return GenericMap<TKeyOut, TValue>
 	 */
-	#[Pure] public function mapKeys(callable $callback): GenericMap;
+	public function mapKeys(callable $callback): GenericMap;
 
 	/**
 	 * @template TOut
@@ -61,37 +61,37 @@ interface ReadonlyMap extends GenericCollection, IteratorAggregate
 	 * @param callable(TValue, TKey): TOut $callback
 	 * @return GenericList<TOut>
 	 */
-	#[Pure] public function reduce(callable $callback): GenericList;
+	public function reduce(callable $callback): GenericList;
 
 	/**
 	 * @param null|callable(TValue, TKey): bool $filter
 	 * @return TValue|null
 	 */
-	#[Pure] public function first(?callable $filter = null): mixed;
+	public function first(?callable $filter = null): mixed;
 
 	/**
 	 * @param null|callable(TKey, TValue): bool $filter
 	 * @return TKey|null
 	 */
-	#[Pure] public function firstKey(?callable $filter = null): mixed;
+	public function firstKey(?callable $filter = null): mixed;
 
 	/**
 	 * @param null|callable(TValue, TKey): bool $filter
 	 * @return bool
 	 */
-	#[Pure] public function any(?callable $filter = null): bool;
+	public function any(?callable $filter = null): bool;
 
 	/**
 	 * @param null|callable(TKey, TValue): bool $filter
 	 * @return bool
 	 */
-	#[Pure] public function anyKey(?callable $filter = null): bool;
+	 public function anyKey(?callable $filter = null): bool;
 
 	/**
 	 * @param TValue $value
 	 * @return bool
 	 */
-	#[Pure] public function contains(mixed $value): bool;
+	public function contains(mixed $value): bool;
 
 	/**
 	 * @return GenericList<TValue>
diff --git a/src/Contract/ReadonlySet.php b/src/Contract/ReadonlySet.php
index 4ce4889..de1391b 100644
--- a/src/Contract/ReadonlySet.php
+++ b/src/Contract/ReadonlySet.php
@@ -13,4 +13,9 @@
  */
 interface ReadonlySet extends GenericCollection, IteratorAggregate
 {
+	/**
+	 * @param T $value
+	 * @return bool
+	 */
+	public function contains(mixed $value): bool;
 }
diff --git a/src/GenericWeakMap.php b/src/GenericWeakMap.php
index 5d3b3a3..8b829db 100644
--- a/src/GenericWeakMap.php
+++ b/src/GenericWeakMap.php
@@ -66,7 +66,7 @@ public function put(mixed $key, mixed $value): void
 		return $this->map->offsetGet($key);
 	}
 
-	#[Pure] public function first(?callable $filter = null): mixed
+	public function first(?callable $filter = null): mixed
 	{
 		/**
 		 * @psalm-suppress ImpureMethodCall
@@ -82,7 +82,7 @@ public function put(mixed $key, mixed $value): void
 		return null;
 	}
 
-	#[Pure] public function firstKey(?callable $filter = null): mixed
+	public function firstKey(?callable $filter = null): mixed
 	{
 		/**
 		 * @psalm-suppress ImpureMethodCall
@@ -102,7 +102,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TValue, TKey): bool $filter
 	 * @return GenericWeakMap<TKey, TValue>
 	 */
-	#[Pure] public function where(callable $filter): GenericWeakMap
+	public function where(callable $filter): GenericWeakMap
 	{
 		/** @var GenericWeakMap<TKey, TValue> $result */
 		$result = new GenericWeakMap();
@@ -125,7 +125,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TKey, TValue): bool $filter
 	 * @return GenericWeakMap<TKey, TValue>
 	 */
-	#[Pure] public function whereKey(callable $filter): GenericWeakMap
+	public function whereKey(callable $filter): GenericWeakMap
 	{
 		/** @var GenericWeakMap<TKey, TValue> $result */
 		$result = new GenericWeakMap();
@@ -161,7 +161,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TValue, TKey): TOut $callback
 	 * @return GenericWeakMap<TKey, TOut>
 	 */
-	#[Pure] public function map(callable $callback): GenericWeakMap
+	public function map(callable $callback): GenericWeakMap
 	{
 		/** @var GenericWeakMap<TKey, TOut> $map */
 		$map = new GenericWeakMap();
@@ -185,7 +185,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TKey, TValue): TKeyOut $callback
 	 * @return GenericWeakMap<TKeyOut, TValue>
 	 */
-	#[Pure] public function mapKeys(callable $callback): GenericWeakMap
+	public function mapKeys(callable $callback): GenericWeakMap
 	{
 		/** @var GenericWeakMap<TKeyOut, TValue> $map */
 		$map = new GenericWeakMap();
@@ -208,7 +208,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TValue, TKey): TOut $callback
 	 * @return ArrayList<TOut>
 	 */
-	#[Pure] public function reduce(callable $callback): ArrayList
+	public function reduce(callable $callback): ArrayList
 	{
 		/** @var ArrayList<TOut> $list */
 		$list = new ArrayList();
@@ -225,12 +225,12 @@ public function put(mixed $key, mixed $value): void
 		return $list;
 	}
 
-	#[Pure] public function any(?callable $filter = null): bool
+	public function any(?callable $filter = null): bool
 	{
 		return $this->first($filter) !== null;
 	}
 
-	#[Pure] public function anyKey(?callable $filter = null): bool
+	public function anyKey(?callable $filter = null): bool
 	{
 		return $this->firstKey($filter) !== null;
 	}
@@ -275,7 +275,7 @@ public function put(mixed $key, mixed $value): void
 		return $list;
 	}
 
-	#[Pure] public function contains(mixed $value): bool
+	public function contains(mixed $value): bool
 	{
 		return $this->any(static fn($item) => $item === $value);
 	}
diff --git a/src/ObjectMap.php b/src/ObjectMap.php
index 68232b9..00b95d7 100644
--- a/src/ObjectMap.php
+++ b/src/ObjectMap.php
@@ -51,7 +51,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param object $key
 	 * @return TValue
 	 */
-	#[Pure] public function get(mixed $key): mixed
+	public function get(mixed $key): mixed
 	{
 		/** @psalm-suppress ImpureMethodCall */
 		if (!$this->map->offsetExists($key)) {
@@ -65,7 +65,7 @@ public function put(mixed $key, mixed $value): void
 		return $this->map->offsetGet($key);
 	}
 
-	#[Pure] public function first(?callable $filter = null): mixed
+	public function first(?callable $filter = null): mixed
 	{
 		/**
 		 * @psalm-suppress ImpureMethodCall
@@ -82,7 +82,7 @@ public function put(mixed $key, mixed $value): void
 		return null;
 	}
 
-	#[Pure] public function firstKey(?callable $filter = null): mixed
+	public function firstKey(?callable $filter = null): mixed
 	{
 		/**
 		 * @psalm-suppress ImpureMethodCall
@@ -106,7 +106,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TValue, TKey): bool $filter
 	 * @return ObjectMap<TKey, TValue>
 	 */
-	#[Pure] public function where(callable $filter): ObjectMap
+	public function where(callable $filter): ObjectMap
 	{
 		/** @var ObjectMap<TKey, TValue> $result */
 		$result = new ObjectMap();
@@ -130,7 +130,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TKey, TValue): bool $filter
 	 * @return ObjectMap<TKey, TValue>
 	 */
-	#[Pure] public function whereKey(callable $filter): ObjectMap
+	public function whereKey(callable $filter): ObjectMap
 	{
 		/** @var ObjectMap<TKey, TValue> $result */
 		$result = new ObjectMap();
@@ -155,7 +155,7 @@ public function put(mixed $key, mixed $value): void
 	 *
 	 * @return bool
 	 */
-	#[Pure] public function has(mixed $key): bool
+	public function has(mixed $key): bool
 	{
 		/** @psalm-suppress ImpureMethodCall */
 		return $this->map->offsetExists($key);
@@ -167,7 +167,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TValue, TKey): TOut $callback
 	 * @return ObjectMap<TKey, TOut>
 	 */
-	#[Pure] public function map(callable $callback): ObjectMap
+	public function map(callable $callback): ObjectMap
 	{
 		/** @var ObjectMap<TKey, TOut> $map */
 		$map = new ObjectMap();
@@ -193,7 +193,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TKey, TValue): TKeyOut $callback
 	 * @return ObjectMap<TKeyOut, TValue>
 	 */
-	#[Pure] public function mapKeys(callable $callback): ObjectMap
+	public function mapKeys(callable $callback): ObjectMap
 	{
 		/** @var ObjectMap<TKeyOut, TValue> $map */
 		$map = new ObjectMap();
@@ -219,7 +219,7 @@ public function put(mixed $key, mixed $value): void
 	 * @param callable(TValue, TKey): TOut $callback
 	 * @return ArrayList<TOut>
 	 */
-	#[Pure] public function reduce(callable $callback): ArrayList
+	public function reduce(callable $callback): ArrayList
 	{
 		/** @var ArrayList<TOut> $list */
 		$list = new ArrayList();
@@ -238,12 +238,12 @@ public function put(mixed $key, mixed $value): void
 		return $list;
 	}
 
-	#[Pure] public function any(?callable $filter = null): bool
+	public function any(?callable $filter = null): bool
 	{
 		return $this->first($filter) !== null;
 	}
 
-	#[Pure] public function anyKey(?callable $filter = null): bool
+	public function anyKey(?callable $filter = null): bool
 	{
 		return $this->firstKey($filter) !== null;
 	}
@@ -283,7 +283,7 @@ public function put(mixed $key, mixed $value): void
 		return $list;
 	}
 
-	#[Pure] public function contains(mixed $value): bool
+	public function contains(mixed $value): bool
 	{
 		return $this->any(static fn($item) => $item === $value);
 	}
diff --git a/src/ObjectSet.php b/src/ObjectSet.php
index f3e0487..84d458e 100644
--- a/src/ObjectSet.php
+++ b/src/ObjectSet.php
@@ -4,12 +4,10 @@
 namespace Elephox\Collection;
 
 use Closure;
-use Elephox\Collection\Contract\GenericCollection;
 use Elephox\Collection\Contract\GenericSet;
 use Elephox\PIE\DefaultEqualityComparer;
 use Elephox\Support\DeepCloneable;
 use InvalidArgumentException;
-use JetBrains\PhpStorm\Pure;
 use SplObjectStorage;
 
 /**
@@ -36,21 +34,6 @@ public function getIterator(): SplObjectStorageIterator
 		return new SplObjectStorageIterator($this->storage);
 	}
 
-	#[Pure] public function first(?callable $filter = null): mixed
-	{
-		// TODO: Implement first() method.
-	}
-
-	#[Pure] public function any(?callable $filter = null): bool
-	{
-		// TODO: Implement any() method.
-	}
-
-	#[Pure] public function where(callable $filter): GenericCollection
-	{
-		// TODO: Implement where() method.
-	}
-
 	public function contains(mixed $value): bool
 	{
 		if (!is_object($value)) {
@@ -85,9 +68,4 @@ public function remove(mixed $value): bool
 
 		return $existed;
 	}
-
-	public function map(callable $callback): GenericCollection
-	{
-		// TODO: Implement map() method.
-	}
 }