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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 OAuthClient( domain, consumer_key, consumer_secret, token, token_secret, user_agent=None, request_encoder=default_request_encoder, response_decoder=default_response_decoder ):
 """Creates a Freshbooks client for a freshbooks domain, using OAuth. Token management is assumed to have been handled out of band. The optional request_encoder and response_decoder parameters can be passed the logging_request_encoder and logging_response_decoder objects from this module, or custom encoders, to aid debugging or change the behaviour of refreshbooks' request-to-XML-to-response mapping. The optional user_agent keyword parameter can be used to specify the user agent string passed to FreshBooks. If unset, a default user agent string is used. """

    return _create_oauth_client(
        AuthorizingClient,
        domain,
        consumer_key,
        consumer_secret,
        token,
        token_secret,
        user_agent=user_agent,
        request_encoder=request_encoder,
        response_decoder=response_decoder
    )