presto-elasticsearch/src/main/java/io/prestosql/elasticsearch/ElasticsearchMetadata.java/ElasticsearchMetadata/getColumnHandles
class ElasticsearchMetadata:    @Override
    public Map<String, ColumnHandle> getColumnHandles(ConnectorSession session, ConnectorTableHandle tableHandle)
    {
        ImmutableMap.Builder<String, ColumnHandle> results = ImmutableMap.builder();

        ConnectorTableMetadata tableMetadata = getTableMetadata(session, tableHandle);
        for (ColumnMetadata column : tableMetadata.getColumns()) {
            results.put(column.getName(), new ElasticsearchColumnHandle(
                    (String) column.getProperties().getOrDefault(ORIGINAL_NAME, column.getName()),
                    column.getType()));
        }

        return results.build();
    }