def METHOD_NAME(self):
    formulae = ["MgO", "FeO", "Fe2Si2O6", "Fe2SiO4"]
    compound_names = ["per", "fper", "fs", "fa"]
    R = sorted(
        reactions_from_formulae(formulae, compound_names, return_strings=True)
    )
    self.assertTrue(R[0] == "2 fa = 2 fper + 1 fs")