code: public function getTokenNotOfKindSibling($index, $direction, array $tokens = [])
      {
          while (true) {
              $index += $direction;
  
              if (!$this->offsetExists($index)) {
                  return null;
              }
  
              if ($this->isEmptyAt($index)) {
                  continue;
              }
  
              if ($this[$index]->equalsAny($tokens)) {
                  continue;
              }
  
              return $index;
          }
      }
docs: Get index for closest sibling token not of given kind.
  
  @param int   $index     token index
  @param int   $direction direction for looking, +1 or -1
  @param array $tokens    possible tokens
  
  @return null|int