<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_header_dict(response, header):
 """ returns a dictionary of the cache control headers the same as is used by django.utils.cache.patch_cache_control if there are no Cache-Control headers returns and empty dict """

    def dictitem(s):
        t = s.split('=', 1)
        if len(t) > 1:
            return (t[0].lower(), t[1])
        else:
            return (t[0].lower(), True)

    if response.has_header(header):
        hd = dict([dictitem(el) for el in cc_delim_re.split(response[header])])
    else:
        hd= {}
    return hd