code: private function addTokenFromBuffer()
      {
          if ($this->_buffer === '') {
              return;
          }
  
          $isKeyword = $this->isKeyword($this->_buffer, $content);
          $this->_currentToken[] = new SqlToken([
              'type' => $isKeyword ? SqlToken::TYPE_KEYWORD : SqlToken::TYPE_TOKEN,
              'content' => is_string($content) ? $content : $this->_buffer,
              'startOffset' => $this->offset - mb_strlen($this->_buffer, 'UTF-8'),
              'endOffset' => $this->offset,
          ]);
          $this->_buffer = '';
      }
docs: Determines a type of text in the buffer, tokenizes it and adds it to the token children.