process method
Implementation
Wait process(
WaitOperation operation, {
required Object? flag,
Object? ref,
}) {
if (operation == WaitOperation.add)
return add(flag: flag, ref: ref);
else if (operation == WaitOperation.remove)
return remove(flag: flag, ref: ref);
else if (operation == WaitOperation.clear)
return clear(flag: flag);
else
throw AssertionError(operation);
}