Each method is implemented as a statically compiled module. This module must provide (and strictly adhere to) a predefined method interface. It supports reliable, ordered delivery and flow control for the protocol that it controls. Aside from meeting these semantics and adhering to the method interface, there are no other restrictions on how the method should be implemented. Support libraries are provided for certain features that are common to many methods, but their use is optional.
Each method is responsible for maintaining the collection of operations that it is working on, usually through operation queues. These collections of operations are private to each method.