>>> dbt.utils.deep_merge({'a': 1, 'b': 2, 'c': 3}, {'a': 2}, {'a': 3, 'b': 1})  # noqa
    {'a': 3, 'b': 1, 'c': 3}

def deep_merge(*args):
    """
    >>> dbt.utils.deep_merge({'a': 1, 'b': 2, 'c': 3}, {'a': 2}, {'a': 3, 'b': 1})  # noqa
    {'a': 3, 'b': 1, 'c': 3}
    """
    if len(args) == 0:
        return None

    if len(args) == 1:
        return copy.deepcopy(args[0])

    lst = list(args)
    last = copy.deepcopy(lst.pop(len(lst) - 1))

    return _deep_merge(deep_merge(*lst), last)