doesn't matter for a test, but I think Collections.singletonList is more efficient than Arrays.asList.
Yeah, that is really miniscule - difference is the allocation of 1 element array and a 10 element array (assuming the Harmony source code is pretty close to the actual), though I like the former for expressing the actual intent.
Don't know why I was specifying both ends of the range - total oversight.
Working on on new patch.
I was experimenting with it a little, and found unexpected behavior when you do a deleter.delete() without first calling setRanges on the deleter. The real BatchScanner (TabletServerBatchReader) throws IllegalStateException("ranges not set") when you get an iterator from it without setting ranges, but the MockBatchScanner does not.
I think that should be handled in a separate patch, though I agree its a problem. Want me to open a new ticket?
Your point also ties back into the bigger issue of the mock instances lagging behind the actual implementation (