# Functions
AddLastAppliedConfiguration add last-applied-configuration and last-applied-time annotation.
GetModifiedConfiguration serializes the object into byte stream.
GetOriginalConfiguration gets original configuration of the object form the annotation, or nil if no annotation found.
ThreeWayMergePatch creates a patch by computing a three way diff based on its current state, modified state, and last-applied-state recorded in the annotation.
# Structs
PatchAction is the action for patch.