public long getMinModifiedProcId() {
    return minModifiedProcId;
  }
Merge the given {@link WALProcedureMap} into this one. The {@link WALProcedureMap} passed in
will be cleared after merging.
hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/store/wal/WALProcedureMap.java