@Override
  protected ProcedureMetrics getProcedureMetrics(MasterProcedureEnv env) {
    return env.getAssignmentManager().getAssignmentManagerMetrics().getAssignProcMetrics();
  }
Leave here only for checking if we can successfully start the master.
@deprecated Do not use any more.
@see TransitRegionStateProcedure
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignProcedure.java