Merge branch '8.x'

Author: GrahamCampbell

Collection.php

@@ -553,6 +553,16 @@ public function isEmpty()
         return empty($this->items);
     }
 
+    /**
+     * Determine if the collection contains a single item.
+     *
+     * @return bool
+     */
+    public function containsOneItem()
+    {
+        return $this->count() === 1;
+    }
+
     /**
      * Join all items from the collection using a string. The final items can use a separate glue string.
      *

LazyCollection.php

@@ -556,6 +556,16 @@ public function isEmpty()
         return ! $this->getIterator()->valid();
     }
 
+    /**
+     * Determine if the collection contains a single item.
+     *
+     * @return bool
+     */
+    public function containsOneItem()
+    {
+        return $this->take(2)->count() === 1;
+    }
+
     /**
      * Join all items from the collection using a string. The final items can use a separate glue string.
      *