Part of twisted.flow.base View Source View In Hierarchy
Known subclasses: twisted.flow.controller.Block, twisted.flow.controller.Deferred
Flow controller
At the base of every flow, is a controller class which interprets the instructions, especially the CallLater instructions. This is primarly just a marker class to denote which classes consume Instruction events. If a controller cannot handle a particular instruction, it raises the Unsupported exception.