docs: def sign_create_cancellation(cancellation_params, key_pair):
      """
      Function to sign the parameters required to create a cancellation request from the Switcheo Exchange.
      Execution of this function is as follows::
  
          sign_create_cancellation(cancellation_params=signable_params, key_pair=key_pair)
  
      The expected return result for this function is as follows::
  
          {
              'order_id': 'aa647b95-d546-4d29-961e-bd62b18b07bf',
              'timestamp': 1542092600331,
              'address': 'fea2b883725ef2d194c9060f606cd0a0468a2c59',
              'signature': '475bc3ecd2310201a3b5357b52b1866aaf5a5618932500e43503ebb....'
          }
  
      :param cancellation_params: Dictionary with Order ID and timestamp to sign for creating the cancellation.
      :type cancellation_params: dict
      :param key_pair: The KeyPair for the wallet being used to sign deposit message.
      :type key_pair: KeyPair
      :return: Dictionary of signed message to send to the Switcheo API.
      """
      encoded_message = encode_message(cancellation_params)
      create_params = cancellation_params.copy()
      create_params['address'] = neo_get_scripthash_from_private_key(private_key=key_pair.PrivateKey).ToString()
      create_params['signature'] = sign_message(encoded_message=encoded_message,
                                                private_key_hex=private_key_to_hex(key_pair=key_pair))
      return create_params