presto-main/src/main/java/io/prestosql/metadata/InternalTable.java/InternalTable/InternalTable
class InternalTable:    public InternalTable(Map<String, Integer> columnIndexes, Iterable<Page> pages)
    {
        this.columnIndexes = ImmutableMap.copyOf(requireNonNull(columnIndexes, "columnIndexes is null"));
        this.pages = ImmutableList.copyOf(requireNonNull(pages, "pages is null"));
    }