Function get_row_encoding_layout 

pub fn get_row_encoding_layout(
    dtypes: &[DataType],
    opts: &[RowEncodingOptions],
    output: RowEncodingOutput,
) -> RowEncodingLayout

The layout for row encoding columns of these logical dtypes. Without dtype-u128, [RowEncodingOutput::Optimal] rows that would be UInt128 are LargeBinary instead.