Added tests for frozenset.
Added tests for frozenset.

ASP1234/voc,gEt-rIgHt-jR/voc,freakboy3742/voc,Felix5721/voc,pombredanne/voc,ASP1234/voc,cflee/voc,Felix5721/voc,pombredanne/voc,cflee/voc,gEt-rIgHt-jR/voc,freakboy3742/voc