// requested session key not found
return null;
} /**
* Returns an array of all files that have been uploaded with this
* request. Each file is represented by an UploadedFile instance.
*/
public function getFiles(): array
{ if ($this->files === null
) { $this->files =
new FileCollection();
} return $this->files->
all(); // return all files
} /**
* Verify if a file exist, by the name of the input field used to upload it, in the collection
* of uploaded files and if is have been uploaded with multiple option.
*
* @return array|null
*/