code: private static void warmup(Argon2 argon2, char[] password) {
          for (int i = 0; i < WARMUP_RUNS; i++) {
              argon2.hash(MIN_ITERATIONS, MIN_MEMORY, MIN_PARALLELISM, password);
          }
      }
docs: Calls Argon2 a number of times to warm up the JIT
  
  @param argon2   Argon2 instance.
  @param password Some password.