presto-kafka/src/main/java/io/prestosql/plugin/kafka/KafkaMetadata.java/KafkaMetadata/listTables
class KafkaMetadata:    @Override
    public List<SchemaTableName> listTables(ConnectorSession session, Optional<String> schemaName)
    {
        ImmutableList.Builder<SchemaTableName> builder = ImmutableList.builder();
        for (SchemaTableName tableName : tableDescriptions.keySet()) {
            if (schemaName.map(tableName.getSchemaName()::equals).orElse(true)) {
                builder.add(tableName);
            }
        }

        return builder.build();
    }