Since mypy doesn't accept redefinition of the same variable within the
same scope, we need to use type annotations with Union to correctly
type aggregate_table. Note that the type cast is necessary for mypy to
narrow the type of aggregate_table.
For types like `Union[Realm, UserProfile, Stream]` and
`Union[AnonymousUser, AbstractBaseUser]`, we need assertions to
tell mypy which type we would be expecting.
When calling some functions or assigning values to certain attributes,
the arguments/right operand do not match the exact type that the
functions/attributes expect, and thus we fix that by converting types
beforehand.
Moving forward we are hoping to collect data on org types from our
users, so it makes sense to display the org type on the "Counts"
tab of our /activity page.
JsonableError has two major benefits over json_error:
* It can be raised from anywhere in the codebase, rather than
being a return value, which is much more convenient for refactoring,
as one doesn't potentially need to change error handling style when
extracting a bit of view code to a function.
* It is guaranteed to contain the `code` property, which is helpful
for API consistency.
Various stragglers are not updated because JsonableError requires
subclassing in order to specify custom data or HTTP status codes.