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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 instance_of(cls):
 """ Create an invariant requiring the value is an instance of ``cls``. """

    def check(value):
        return (
            isinstance(value, cls),
            u"{value!r} is instance of {actual!s}, required {required!s}".format(
                value=value,
                actual=fullyQualifiedName(type(value)),
                required=fullyQualifiedName(cls),
            ),
        )
    return check