presto-memory/src/main/java/io/prestosql/plugin/memory/MemoryMetadata.java/MemoryMetadata/listTables
class MemoryMetadata:    @Override
    public synchronized List<SchemaTableName> listTables(ConnectorSession session, Optional<String> schemaName)
    {
        return tables.values().stream()
                .filter(table -> schemaName.map(table.getSchemaName()::equals).orElse(true))
                .map(TableInfo::getSchemaTableName)
                .collect(toList());
    }