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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 find_subclass(base: type, name: str) -> type: """Find a named subclass of a base class. Uses only the class name without namespace. """

    class_candidates = [klass
                        for klass in all_subclasses(base)
                        if klass.__name__ == name
                        ]
    if len(class_candidates) == 0:
        raise RuntimeError("No \"{0}\" subclass of \"{1}\".".format(base.__name__, name))
    elif len(class_candidates) > 1:
        raise RuntimeError("Multiple \"{0}\" subclasses of \"{1}\".".format(base.__name__, name))
    return class_candidates[0]