def METHOD_NAME(self):
    second_variables_list = [InputVariable('eta', size=3, index=0),
                             InputVariable('eta_dot', size=3, index=1)]
    second_vector = LinearVector(second_variables_list)
    merged_vector = LinearVector.merge(self.input_variables, second_vector)
    assert merged_vector[-1].name == 'eta_dot', 'Vectors not coupled properly'
    assert merged_vector[2].name == 'u_gust', 'Vectors not coupled properly'