Tests for reslicing

Increasing coverage and adding tests for reslicing as promised!


As in other cases (where peaks_for_model comes from ), this adds (unnecessary?)  complexity, and complexity adds a maintenance burden. You might remember what this means a year from now, because you wrote this, but a new developers will look at this and puzzle. If you think the original name is no good (I tend to agree with you), we can change it, and do it in the way you are proposing here, but that also means making a plan to slowly deprecate the other name. So, adding at the very least a note in the documentation warning others of this would be appropriate.