reduce deprecation notices from later PHP versions

src/Collection/ArraySequence.php

@@ -141,6 +141,7 @@ public function offsetExists($offset) : bool
         return isset($this->array[$offset]);
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         if (!isset($this->array[$offset])) {

src/Collection/EmptySequence.php

@@ -94,6 +94,7 @@ public function offsetExists($offset) : bool
         return false;
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         return null;

src/Collection/PromiseSequence.php

@@ -191,6 +191,7 @@ public function offsetExists($offset) : bool
         return $this->wait()->offsetExists($offset);
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         return $this->wait()->offsetGet($offset);

src/ImmutableArrayAccess.php

@@ -6,12 +6,12 @@
 
 trait ImmutableArrayAccess
 {
-    final public function offsetSet($offset, $value)
+    final public function offsetSet($offset, $value): void
     {
         throw new BadMethodCallException('Object is immutable');
     }
 
-    final public function offsetUnset($offset)
+    final public function offsetUnset($offset): void
     {
         throw new BadMethodCallException('Object is immutable');
     }

src/Model/SearchSubjects.php

@@ -19,33 +19,35 @@ public function __construct(array $subjects, array $results)
         $this->results = $results;
     }
 
-    public function count()
+    public function count(): int
     {
         return count($this->subjects);
     }
 
+    #[\ReturnTypeWillChange]
     public function current()
     {
         return current($this->results);
     }
 
-    public function next()
+    public function next(): void
     {
         next($this->subjects);
         next($this->results);
     }
 
+    #[\ReturnTypeWillChange]
     public function key()
     {
         return current($this->subjects);
     }
 
-    public function valid()
+    public function valid(): bool
     {
         return false !== $this->key();
     }
 
-    public function rewind()
+    public function rewind(): void
     {
         reset($this->subjects);
         reset($this->results);

src/Model/SearchTypes.php

@@ -19,7 +19,7 @@ public function __construct(array $typesToResults)
         $this->typesToResults = $typesToResults;
     }
 
-    public function count()
+    public function count(): int
     {
         return count($this->typesToResults);
     }

src/SlicedArrayAccess.php

@@ -14,6 +14,7 @@ public function offsetExists($offset) : bool
         return null !== $this->offsetGet($offset);
     }
 
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         try {

src/SlicedIterator.php

@@ -10,6 +10,7 @@ trait SlicedIterator
 
     private $key = 1;
 
+    #[\ReturnTypeWillChange]
     final public function current()
     {
         $page = (int) ceil($this->key / $this->pageBatch);
@@ -23,11 +24,12 @@ final public function current()
         return $pageContents[$inPage];
     }
 
-    final public function next()
+    final public function next(): void
     {
         ++$this->key;
     }
 
+    #[\ReturnTypeWillChange]
     final public function key()
     {
         if ($this->key > $this->count()) {
@@ -37,12 +39,12 @@ final public function key()
         return $this->key;
     }
 
-    final public function valid()
+    final public function valid(): bool
     {
         return $this->key <= $this->count();
     }
 
-    final public function rewind()
+    final public function rewind(): void
     {
         $this->key = 1;
     }