@Override
    public boolean isMergeEnabled() {
      return getOrDefault(MERGE_ENABLED_KEY, Boolean::valueOf, DEFAULT_MERGE_ENABLED);
    }
Check if the region merge enable flag of the table is true. If flag is false then no merge
will be done.
@return true if table region merge enabled
hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptorBuilder.java