presto-blackhole/src/main/java/io/prestosql/plugin/blackhole/BlackHolePageSourceProvider.java/BlackHolePageSourceProvider/generateZeroPage
class BlackHolePageSourceProvider:    private Page generateZeroPage(List<Type> types, int rowsCount, int fieldLength)
    {
        byte[] constantBytes = new byte[fieldLength];
        Arrays.fill(constantBytes, (byte) 42);
        Slice constantSlice = Slices.wrappedBuffer(constantBytes);

        Block[] blocks = new Block[types.size()];
        for (int i = 0; i < blocks.length; i++) {
            blocks[i] = createZeroBlock(types.get(i), rowsCount, constantSlice);
        }

        return new Page(rowsCount, blocks);
    }