def METHOD_NAME(tmpdir, ala_traj):
    mols = ala_traj.clone()
    assert mols.num_frames() == 500
    mol = mols[0]
    mols.load_frame(100)
    d = tmpdir.mkdir("test_ignore_topology_frame")
    pdb = sr.save(mols, d.join("test"), format=["PDB"])
    rst = sr.save(mols.trajectory()[0:10], d.join("test"), format=["RST"])
    # load including the PDB frame... - the should be the same
    # as the 100th frame (as this was saved as the PDB)
    mols2 = sr.load(pdb + rst)
    assert mols2.num_frames() == 11
    assert_coords_equal(mols[0], mols2[0], 0.001)
    # load ignoring the PDB frame - this should be the same as the loaded
    # molecule that was frame 0 of the TRAJ file
    mols2 = sr.load(pdb + rst, ignore_topology_frame=True)
    assert mols2.num_frames() == 10
    assert_coords_equal(mol, mols2[0], 0.001)