code: public function find_by($field, $value, $fields = '*', $order = NULL)
      {
          $arg_list = array();
          if (is_array($value)) {
              $arg_list = $value;
              $value    = $arg_list[0];
          }
          $fields = isset($arg_list[1]) ? $arg_list[1] : $fields;
          $order  = isset($arg_list[2]) ? $arg_list[2] : $order;
  
          $where = array($field => $value);
          return $this->find($where, $fields, $order);
      }
docs: @param        $field
  @param        $value
  @param string $fields
  @param null   $order
  
  @return bool