code: protected function parse_adjacent() {
  		$tmp = $this->result;
  		$this->result = array();
  		if (($c = $this->parse_conditions()) === false) {
  			return false;
  		}
  
  		foreach($tmp as $t) {
  			if (($sibling = $t->getNextSibling()) !== false) {
  				if ($sibling->match($c, true, $this->custom_filter_map)) {
  					$this->result[] = $sibling;
  				}
  			}
  		}
  
  		return true;
  	}
docs: Evaluate sibling nodes
  @return bool
  @internal Result of query is set in {@link $result}
  @access private