presto-local-file/src/main/java/io/prestosql/plugin/localfile/LocalFileRecordCursor.java/LocalFileRecordCursor/getType
class LocalFileRecordCursor:    @Override
    public Type getType(int field)
    {
        checkArgument(field < columns.size(), "Invalid field index");
        return columns.get(field).getColumnType();
    }