Executor e = c.getExecutors().get(0);
when(e.isIdle()).thenReturn(false);
when(e.getEstimatedRemainingTimeMillis()).thenReturn(300L);
JobOffer o = createMockOffer(c.getExecutors().get(1));
MappingWorksheet mw = new MappingWorksheet(wrap(t), asList(o));
// since the currently busy executor will free up before a future predicted load starts,
// we should have a valid executor remain in the queue