<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def gen_rst_url_split_opts(opts_str):
 """generate option list for RST docs Parameters opts_str : str a string including all SUEWS related options/variables. e.g. 'SUEWS_a, SUEWS_b' Returns ------- list a list of parsed RST `:ref:` roles. e.g. [':option:`SUEWS_a <suews:SUEWS_a>`'] """

    if opts_str is not 'None':
        list_opts = opts_str.split(',')
        # list_rst = [gen_rst_url_opt(opt.strip()) for opt in list_opts]
        list_rst = [opt.strip() for opt in list_opts]
        # list_rst = [f'`{opt}`' for opt in list_rst]
        # more properly handle SUEWS options by explicitly adding prefix `suews`:
        list_rst = [f':option:`{opt} <suews:{opt}>`' for opt in list_rst]
        list_url_rst = ', '.join(list_rst)
    else:
        list_url_rst = 'None'
    return list_url_rst