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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 update_custom_field(self, custom_field_key, field_name, visible_in_preference_center):
 """Updates a custom field belonging to this list."""

        custom_field_key = quote(custom_field_key, '')
        body = {
            "FieldName": field_name,
            "VisibleInPreferenceCenter": visible_in_preference_center}
        response = self._put(self.uri_for("customfields/%s" %
                                          custom_field_key), json.dumps(body))
        return json_to_py(response)