Implements a 'use_slave' context manager and decorator that can be used in cases where the usual behavior would be to pin to master, such as when the request method is POST, but you know you're not doing any writing.
Implements a 'use_slave' context manager and decorator that can be used in cases where the usual behavior would be to pin to master, such as when the request method is POST, but you know you're not doing any writing.