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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _merge_a_into_b(self, a, b):
 """Merge config dictionary a into config dictionary b, clobbering the options in b whenever they are also specified in a. """

        from easydict import EasyDict as edict
        if type(a) is not edict:
            return

        for k, v in a.items():
            # a must specify keys that are in b
            if k not in b:
                raise KeyError('{} is not a valid config key'.format(k))

            # the types must match, too
            old_type = type(b[k])
            if old_type is not type(v):
                if isinstance(b[k], np.ndarray):
                    v = np.array(v, dtype=b[k].dtype)
                else:
                    raise ValueError(('Type mismatch ({} vs. {}) '
                                      'for config key: {}').format(type(b[k]),
                                                                   type(v), k))

            # recursively merge dicts
            if type(v) is edict:
                try:
                    self._merge_a_into_b(a[k], b[k])
                except:
                    print('Error under config key: {}'.format(k))
                    raise
            else:
                b[k] = v
        return b