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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 create_dummy_func(func, dependency):
 """ When a dependency of a function is not available, create a dummy function which throws ImportError when used. Args: func (str):
 name of the function. dependency (str or list[str]):
 name(s) of the dependency. Returns: function: a function object """

    assert not building_rtfd()

    if isinstance(dependency, (list, tuple)):
        dependency = ','.join(dependency)

    def _dummy(*args, **kwargs):
        raise ImportError("Cannot import '{}', therefore '{}' is not available".format(dependency, func))
    return _dummy