Source code for the HK-RVEA algorithm: Chugh, T., Allmendinger, R., Ojalehto, V., Miettinen, K., Surrogate-assisted Evolutionary Biobjective Optimization for Objectives with Non-uniform Latencies, in "Proceedings of the Genetic and Evolutionary Computation Conference (GECCO-2018)", Ed. by H. Aguirre, The Association of Computing Machinery (ACM), 609-616, 2018