protected boolean tableExists(TableName table, Connection conn) throws IOException {
    try (Admin admin = conn.getAdmin()) {
      return admin.tableExists(table);
    }
  }
@throws IOException                   If the execution of the backup fails
@throws ColumnFamilyMismatchException If the column families of the current table do not match
                                      the column families for the last full backup. In which
                                      case, a full backup should be taken
hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/impl/IncrementalTableBackupClient.java