code: public boolean shouldDoInitialLoad() {
          if (role.is(Role.SENDER_BACKUP)) {
              // was backup. become primary sender
              role.next(Role.SENDER);
  
              if (state.is(State.LOADING)) {
                  // previous loading was in progress. cancel and start from scratch
                  state.next(State.NOT_LOADED);
                  keyLoadFinished.setResult(false);
              }
          }
  
          return state.is(State.NOT_LOADED);
      }
docs: Returns {@code true} if the keys are not loaded yet, promoting this key
  loader and resetting the loading state if necessary in the process.
  If this gets invoked on SENDER BACKUP it means the SENDER died and
  SENDER BACKUP takes over.