Violet Sherratt

Can I just raise that this is a perfectly valid way to define a method: ```python def collapsed(self, coords, aggregator, **kwargs): pass # actual contents of Cube.collapsed here... class Cube:...

Just to clarify: both available solutions there would still *not* support `rotated_mercator` directly, because that is not a recognised grid mapping in the [CF conventions](http://cfconventions.org/Data/cf-conventions/cf-conventions-1.9/cf-conventions.html#appendix-grid-mappings). What they *would* support is...

One option which seemed favourable in peloton discussions: adding a `__format__` method to `Coord`, such that `format(tcoord, "%Y-%m-%d")` could be used to create a string with all points formatted with...