presto-accumulo/src/main/java/io/prestosql/plugin/accumulo/AccumuloMetadata.java/AccumuloMetadata/getColumnHandles
class AccumuloMetadata:    @Override
    public Map<String, ColumnHandle> getColumnHandles(ConnectorSession session, ConnectorTableHandle tableHandle)
    {
        AccumuloTableHandle handle = (AccumuloTableHandle) tableHandle;

        AccumuloTable table = client.getTable(handle.toSchemaTableName());
        if (table == null) {
            throw new TableNotFoundException(handle.toSchemaTableName());
        }

        ImmutableMap.Builder<String, ColumnHandle> columnHandles = ImmutableMap.builder();
        for (AccumuloColumnHandle column : table.getColumns()) {
            columnHandles.put(column.getName(), column);
        }
        return columnHandles.build();
    }