Merge config dictionary a into config dictionary b, clobbering the
        options in b whenever they are also specified in a. Do not do any checking.

def _merge_a_into_b_simple(self, a, b):
        """Merge config dictionary a into config dictionary b, clobbering the
        options in b whenever they are also specified in a. Do not do any checking.
        """
        for k, v in a.items():
            b[k] = v
        return b