'For a sink/source, return it\'s module id in our cache, if found.'

def get_module_idx(self, sink_name, source_name):

    result = re.search(str.format(MOD_REGEX, re.escape(sink_name), re.escape(source_name)), self._current_module_state)
    if (result and result.group(1).isdigit()):
        return int(result.group(1))
    return (-1)
