presto-example-http/src/main/java/io/prestosql/plugin/example/ExampleMetadata.java/ExampleMetadata/getColumnMetadata
class ExampleMetadata:    @Override
    public ColumnMetadata getColumnMetadata(ConnectorSession session, ConnectorTableHandle tableHandle, ColumnHandle columnHandle)
    {
        return ((ExampleColumnHandle) columnHandle).getColumnMetadata();
    }