original_string: public function getCredentialValidationCallback()
      {
          if ($this->checkOldHashes) {
              $credentialValidationCallback = function($dbCredential, $requestCredential) {
                  if (password_verify($requestCredential, $dbCredential)) {
                      return true;
                  } elseif ($dbCredential == $this->hashOldPassword($requestCredential)) {
                      return true;
                  }
  
                  return false;
              };
          } else {
              $credentialValidationCallback = function($dbCredential, $requestCredential) {
                  if (password_verify($requestCredential, $dbCredential)) {
                      return true;
                  }
  
                  return false;
              };
          }
  
          return $credentialValidationCallback;
      }
code: public function getCredentialValidationCallback()
      {
          if ($this->checkOldHashes) {
              $credentialValidationCallback = function($dbCredential, $requestCredential) {
                  if (password_verify($requestCredential, $dbCredential)) {
                      return true;
                  } elseif ($dbCredential == $this->hashOldPassword($requestCredential)) {
                      return true;
                  }
  
                  return false;
              };
          } else {
              $credentialValidationCallback = function($dbCredential, $requestCredential) {
                  if (password_verify($requestCredential, $dbCredential)) {
                      return true;
                  }
  
                  return false;
              };
          }
  
          return $credentialValidationCallback;
      }
code_tokens: public function getCredentialValidationCallback ( ) { if ( $ this -> checkOldHashes ) { $ credentialValidationCallback = function ( $ dbCredential , $ requestCredential ) { if ( password_verify ( $ requestCredential , $ dbCredential ) ) { return true ; } elseif ( $ dbCredential == $ this -> hashOldPassword ( $ requestCredential ) ) { return true ; } return false ; } ; } else { $ credentialValidationCallback = function ( $ dbCredential , $ requestCredential ) { if ( password_verify ( $ requestCredential , $ dbCredential ) ) { return true ; } return false ; } ; } return $ credentialValidationCallback ; }
docstring: get the credential validation callback function for the callback check adapter
  @return callback Function
docstring_tokens: get the credential validation callback function for the callback check adapter