def METHOD_NAME(self):
    structure = self.project.create.structure.ase.bulk("Cu", cubic=True).repeat(5)
    self.job.potential = "2001--Mishin-Y--Cu-1--LAMMPS--ipr1"
    self.job.structure = structure
    self.job.write_structure(structure, "test.dump", ".")
    self.assertEqual(os.path.exists("test.dump"), True)
    self.assertEqual(self.job._number_of_structures(), 2)