How do we use google-test for sums of sets

[holke]

Asked originally by @Davknapp in #255

Google-test provides good functionality for testing over the product of tests. But testing over sums of sets, for example
set1 = {1, 2, 3, 4} set2 = {5, 6, 7}
shows some drawbacks. Especially when only one line of code has to be changed between the testing of the parameters in set1 and set2.
Is there a better way to tests over the sum of parameters using googletest?