/**
  * Returns document object
  *
  * @param string $documentName
  * @return \Migration\ResourceModel\Document|false
  */
 public function getDocument($documentName)
 {
     $documentList = $this->getDocumentList();
     if (!in_array($documentName, $documentList)) {
         return false;
     }
     $structure = $this->getStructure($documentName);
     return $this->documentFactory->create(['structure' => $structure, 'documentName' => $documentName]);
 }