public function is(callable $callback) {
    foreach ($this->nodes as $node) {
      if ($callback($node)) {
        return TRUE;
      }
    }
    return FALSE;
  }
public function is(callable $callback) {
    foreach ($this->nodes as $node) {
      if ($callback($node)) {
        return TRUE;
      }
    }
    return FALSE;
  }
public function is ( callable $ callback ) { foreach ( $ this -> nodes as $ node ) { if ( $ callback ( $ node ) ) { return TRUE ; } } return FALSE ; }
Test is any element in collection matches.

@param callable $callback
Callback to test for node match.

@return boolean
TRUE if any element in set of nodes matches.
Test is any element in collection matches .