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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 load_subclasses(klass, modules=None):
 """Load recursively all all subclasses from a module. Args: klass (str or list of str):
 Class whose subclasses we want to load. modules: List of additional modules or module names that should be recursively imported in order to find all the subclasses of the desired class. Default: None FIXME: This function is kept only for backward compatibility reasons, it should not be used. Deprecation warning should be raised and it should be replaces by the ``Loader`` class. """

    if modules:
        if isinstance(modules, six.string_types):
            modules = [modules]
        loader = Loader()
        loader.load(*modules)
    return klass.__subclasses__()