<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def check_for_missing_options(config):
 """Iter over a config and raise if a required option is still not set. Args: config (confpy.core.config.Configuration):
 The configuration object to validate. Raises: MissingRequiredOption: If any required options are not set in the configuration object. Required options with default values are considered set and will not cause this function to raise. """

    for section_name, section in config:

        for option_name, option in section:

            if option.required and option.value is None:

                raise exc.MissingRequiredOption(
                    "Option {0} in namespace {1} is required.".format(
                        option_name,
                        section_name,
                    )
                )

    return config