For constructing test scripts, use std::vector and, in particular,
std::vector::insert to insert 20 zero bytes rather than listing the full
array of bytes explicitly. This makes the code easier to read and makes
it immediately obvious what the structure of the data is, without having
to count the zeros to understand it.
This value doesn't affect the outcome of the test, because the values are
properly set on line 351, but this makes the test values internally coherent.