/**
  * {@inheritdoc}
  */
 public function walkSubSelect($subselect)
 {
     $this->inSubSelect = true;
     $sql = parent::walkSubselect($subselect);
     $this->inSubSelect = false;
     return $sql;
 }
 /**
  * {@inheritDoc}
  */
 public function walkSubselect($subselect)
 {
     $result = parent::walkSubselect($subselect);
     return $result;
 }
 /**
  * {@inheritDoc}
  */
 public function walkSubselect($subselect)
 {
     $this->processedNestingLevel++;
     $result = parent::walkSubselect($subselect);
     return $result;
 }