code: private function tokenizeDelimitedString(&$length)
      {
          $isIdentifier = $this->isIdentifier($length, $content);
          $isStringLiteral = !$isIdentifier && $this->isStringLiteral($length, $content);
          if (!$isIdentifier && !$isStringLiteral) {
              return false;
          }
  
          $this->addTokenFromBuffer();
          $this->_currentToken[] = new SqlToken([
              'type' => $isIdentifier ? SqlToken::TYPE_IDENTIFIER : SqlToken::TYPE_STRING_LITERAL,
              'content' => is_string($content) ? $content : $this->substring($length),
              'startOffset' => $this->offset,
              'endOffset' => $this->offset + $length,
          ]);
          return true;
      }
docs: Determines whether there is a delimited string at the current offset and adds it to the token children.
  @param int $length
  @return bool