'Given a check, return the default value for the check
(converted to the right type).
If the check doesn\'t specify a default value then a
``KeyError`` will be raised.'

def get_default_value(self, check):

    (fun_name, fun_args, fun_kwargs, default) = self._parse_with_caching(check)
    if (default is None):
        raise KeyError(('Check    "%s"    has    no    default    value.' % check))
    value = self._handle_none(default)
    if (value is None):
        return value
    return self._check_value(value, fun_name, fun_args, fun_kwargs)
