assertEquals() has poor output for sets

[mdbooth]

testtools.assertEquals(set1, set2) will display both sets in full. However unittest.assertSetEquals() displays a nice diff. testtools.assertEquals() should either pass through to unittest.assertSetEquals(), or print its own nice diff.

[rbtcollins]

Hi. Does unittest.assertEquals call assertSetEquals itself?

What version of Python was assertSetEquals added in? We need to backport things to 2.6+.

Our assertEquals is
self.assertThat(left, Equals(right))

So teaching Equals to be smarter about containers etc - e.g. delegating to a type sensitive matcher - would be good.