presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/thrift/BridgingHiveMetastore.java/BridgingHiveMetastore/commentTable
class BridgingHiveMetastore:    @Override
    public void commentTable(HiveIdentity identity, String databaseName, String tableName, Optional<String> comment)
    {
        Optional<org.apache.hadoop.hive.metastore.api.Table> source = delegate.getTable(identity, databaseName, tableName);
        if (!source.isPresent()) {
            throw new TableNotFoundException(new SchemaTableName(databaseName, tableName));
        }
        org.apache.hadoop.hive.metastore.api.Table table = source.get();

        Map<String, String> parameters = table.getParameters().entrySet().stream()
                .filter(entry -> !entry.getKey().equals(TABLE_COMMENT))
                .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
        comment.ifPresent(value -> parameters.put(TABLE_COMMENT, comment.get()));

        table.setParameters(parameters);
        alterTable(identity, databaseName, tableName, table);
    }