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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 encode_unicode(f):
 """Cerberus error messages expect regular binary strings. If unicode is used in a ValidationError message can't be printed. This decorator ensures that if legacy Python is used unicode strings are encoded before passing to a function. """

    @wraps(f)
    def wrapped(obj, error):

        def _encode(value):
            """Helper encoding unicode strings into binary utf-8"""
            if isinstance(value, unicode):  # noqa: F821
                return value.encode('utf-8')
            return value

        error = copy(error)
        error.document_path = _encode(error.document_path)
        error.schema_path = _encode(error.schema_path)
        error.constraint = _encode(error.constraint)
        error.value = _encode(error.value)
        error.info = _encode(error.info)
        return f(obj, error)

    return wrapped if PYTHON_VERSION < 3 else f