Set proper serialization tag.
Make the per-spec test easier to follow.
Keep the serialized name in sync with the field name.
Drop a superfluous empty line.
Drop an unnecessary check in a test.
Add a test for an empty availability zone.
Add a note about why we use bson.M.
Clarify a doc comment.
gc.DeepEquals -> jc.DeepEquals.
provcommon -> common.