public function visitReturn(ReturnCommand $x, Context $ctx)
 {
     // R4~...values...
     $this->appendTypedData(RETURN_TYPE, count($x->getValues()));
     return true;
 }
 public function visitReturn(ReturnCommand $x, Context $ctx)
 {
     $values = $x->getValues();
     $size = count($values);
     $this->beginRpc($x);
     $this->_return();
     // return [a,b,c];
     $this->lbracket();
     for ($i = 0; $i < $size; $i++) {
         $this->accept($values[$i]);
         if ($i < $size - 1) {
             $this->comma();
         }
     }
     $this->rbracket();
     $this->semi();
     $this->commit($x);
     return false;
 }