code: public function setField($selector, $value)
      {
          if (is_integer($this->focus)) {
              $this->frames[$this->focus]->setField($selector, $value);
          } else {
              for ($i = 0; $i < count($this->frames); $i++) {
                  $this->frames[$i]->setField($selector, $value);
              }
          }
      }
docs: Sets a field on each form in which the field is available.
  
  @param SimpleSelector $selector    Field finder.
  @param string $value               Value to set field to.
  
  @return bool                    True if value is valid.