protected static String extractSnapshotNameFromSizeCell(Cell c) {
    return Bytes.toString(c.getQualifierArray(),
      c.getQualifierOffset() + QUOTA_SNAPSHOT_SIZE_QUALIFIER.length,
      c.getQualifierLength() - QUOTA_SNAPSHOT_SIZE_QUALIFIER.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