def read_arg(src, c):
content = [c]<EOL>while src.hasNext():<EOL><INDENT>if src.peek() in ARG_END_TOKENS:<EOL><INDENT>content.append(next(src))<EOL>break<EOL><DEDENT>else:<EOL><INDENT>content.append(read_tex(src))<EOL><DEDENT><DEDENT>return Arg.parse(content)<EOL>
Read the argument from buffer.

    Advances buffer until right before the end of the argument.

    :param Buffer src: a buffer of tokens
    :param str c: argument token (starting token)
    :return: the parsed argument
    :rtype: Arg