presto-kudu/src/main/java/io/prestosql/plugin/kudu/KuduMetadata.java/KuduMetadata/getColumnHandles
class KuduMetadata:    @Override
    public Map<String, ColumnHandle> getColumnHandles(ConnectorSession session, ConnectorTableHandle connectorTableHandle)
    {
        KuduTableHandle tableHandle = (KuduTableHandle) connectorTableHandle;
        Schema schema = clientSession.getTableSchema(tableHandle);

        ImmutableMap.Builder<String, ColumnHandle> columnHandles = ImmutableMap.builder();
        for (int ordinal = 0; ordinal < schema.getColumnCount(); ordinal++) {
            ColumnSchema col = schema.getColumnByIndex(ordinal);
            String name = col.getName();
            Type type = TypeHelper.fromKuduColumn(col);
            KuduColumnHandle columnHandle = new KuduColumnHandle(name, ordinal, type);
            columnHandles.put(name, columnHandle);
        }

        return columnHandles.build();
    }