presto-thrift/src/main/java/io/prestosql/plugin/thrift/ThriftMetadata.java/ThriftMetadata/getRequiredTableMetadata
class ThriftMetadata:    private ThriftTableMetadata getRequiredTableMetadata(SchemaTableName schemaTableName)
    {
        Optional<ThriftTableMetadata> table = tableCache.getUnchecked(schemaTableName);
        if (!table.isPresent()) {
            throw new TableNotFoundException(schemaTableName);
        }
        else {
            return table.get();
        }
    }