@Override
    public long getMaxFileSize() {
      return getOrDefault(MAX_FILESIZE_KEY, Long::valueOf, (long) -1);
    }
Returns the maximum size upto which a region can grow to after which a region split is
triggered. The region size is represented by the size of the biggest store file in that
region.
@return max hregion size for table, -1 if not set.
@see #setMaxFileSize(long)
hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptorBuilder.java