code: function getDelim() {
    const type = NodeType.DelimType;
    const token = tokens[pos];
    const line = token.ln;
    const column = token.col;
    const content = ',';
  
    pos++;
  
    return newNode(type, content, line, column);
  }
docs: Get node with a comma
  @return {Array} `['delim']`