Python codegen instance of incorrect indentation in `ApiClient.sanitize_for_serialization`.
The python code gen has an instance of incorrect indentation that is causing all API requests to fail.
In `api_client.ApiClient.sanitize_for_serialization`, the block of code that handles the case when `obj` is a dictionary is indented too far. Since python is whitespace sensitive, this causes this block to be scoped under the preceding if block, meaning it never runs. Execution falls off the edge of the function, resulting in a return value of None, which of course immediately throws an exception the second the value is accessed.
