protected static TableName getTableFromRowKey(final byte[] key) {
    return TableName.valueOf(Bytes.toString(key, QUOTA_TABLE_ROW_KEY_PREFIX.length));
  }
Returns the current space quota snapshot of the given {@code tableName} from
{@code QuotaTableUtil.QUOTA_TABLE_NAME} or null if the no quota information is available for
that tableName.
@param conn      connection to re-use
@param tableName name of the table whose current snapshot is to be retreived
hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaTableUtil.java