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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 occurs_in_type(v, type2):
 """Checks whether a type variable occurs in a type expression. Note: Must be called with v pre-pruned Args: v: The TypeVariable to be tested for type2: The type in which to search Returns: True if v occurs in type2, otherwise False """

    pruned_type2 = prune(type2)
    if pruned_type2 == v:
        return True
    elif isinstance(pruned_type2, TypeOperator):
        return occurs_in(v, pruned_type2.types)
    return False