original_string: public function allowEmptyDate($field, $when = true, $message = null)
      {
          return $this->allowEmptyFor($field, self::EMPTY_STRING | self::EMPTY_DATE, $when, $message);
      }
code: public function allowEmptyDate($field, $when = true, $message = null)
      {
          return $this->allowEmptyFor($field, self::EMPTY_STRING | self::EMPTY_DATE, $when, $message);
      }
code_tokens: public function allowEmptyDate ( $ field , $ when = true , $ message = null ) { return $ this -> allowEmptyFor ( $ field , self :: EMPTY_STRING | self :: EMPTY_DATE , $ when , $ message ) ; }
docstring: Allows a field to be an empty date.
  
  This method is equivalent to calling allowEmptyFor() with EMPTY_STRING +
  EMPTY_DATE flags.
  
  @param string $field The name of the field.
  @param bool|string|callable $when Indicates when the field is allowed to be empty
  Valid values are true, false, 'create', 'update'. If a callable is passed then
  the field will allowed to be empty only when the callback returns true.
  @param string|null $message The message to show if the field is not
  @return $this
  @since 3.7.0
  @see \Cake\Validation\Validator::allowEmptyFor() For detail usage
docstring_tokens: Allows a field to be an empty date .