public static void dropTag(Table table, AlterTableSnapshotRefSpec.DropSnapshotRefSpec dropTagSpec) {
    String tagName = dropTagSpec.getRefName();
    boolean ifExists = dropTagSpec.getIfExists();

    SnapshotRef snapshotRef = table.refs().get(tagName);
    if (snapshotRef != null || !ifExists) {
      LOG.info("Dropping tag {} on iceberg table {}", tagName, table.name());
      table.manageSnapshots().removeTag(tagName).commit();
    }
  }
Create a branch on the iceberg table
@param table the iceberg table
@param createBranchSpec Get the basic parameters needed to create a branch
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/hive/IcebergSnapshotRefExec.java