code: public static function select($select)
      {
          if (gettype($select)=="array") {
              foreach ($select as $key => $field) {
                  if ($field instanceof Key) {
                      $alias =  '"'.$field.'"';
                      $field =  self::field($field);
                      $select[$key] = "{$field} as {$alias}";
                  }
              }
              $select = implode(", ", $select);
          } elseif (gettype($select)!="string") {
              throw new ClusterpointException("\"->select()\" function: passed parametr is not in valid format.", 9002);
          }
          return $select;
      }
docs: Pass back SELECT clause string to set in scope.
  
  @param  mixed  $select
  @return string