Add nextPage() method to LengthAwarePaginator.

src/Illuminate/Pagination/LengthAwarePaginator.php

@@ -162,6 +162,16 @@ public function hasMorePages()
         return $this->currentPage() < $this->lastPage();
     }
 
+    /**
+     * Get the next page.
+     *
+     * @return int|null
+     */
+    public function nextPage(): ?int
+    {
+        return $this->hasMorePages() ? $this->currentPage() + 1 : null;
+    }
+
     /**
      * Get the URL for the next page.
      *
@@ -199,6 +209,7 @@ public function toArray()
             'last_page' => $this->lastPage(),
             'last_page_url' => $this->url($this->lastPage()),
             'links' => $this->linkCollection()->toArray(),
+            'next_page' => $this->nextPage(),
             'next_page_url' => $this->nextPageUrl(),
             'path' => $this->path(),
             'per_page' => $this->perPage(),