// Helper methods for the tests.
func AssertValues(c *gc.C, s set.Strings, expected ...string) {
values := s.Values()
// Expect an empty slice, not a nil slice for values.
if expected == nil {
expected = []string{}
}
sort.Strings(expected)
sort.Strings(values)
c.Assert(values, gc.DeepEquals, expected)
c.Assert(s.Size(), gc.Equals, len(expected))
// Check the sorted values too.
sorted := s.SortedValues()
c.Assert(sorted, gc.DeepEquals, expected)
}