presto-orc/src/main/java/io/prestosql/orc/OrcWriter.java/OrcWriter/toColumnMetadata
class OrcWriter:    private static <T> ColumnMetadata<T> toColumnMetadata(Map<OrcColumnId, T> data, int expectedSize)
    {
        checkArgument(data.size() == expectedSize);
        List<T> list = new ArrayList<>(expectedSize);
        for (int i = 0; i < expectedSize; i++) {
            list.add(data.get(new OrcColumnId(i)));
        }
        return new ColumnMetadata<>(ImmutableList.copyOf(list));
    }