maps__merge_in
ret = maps__merge_in(maps, map_kcore1);
ret = maps__merge_in(maps, map_kcore2);
ret = maps__merge_in(maps, map_kcore3);
TEST_CASE("Test merge_in interface", maps__merge_in),
int maps__merge_in(struct maps *kmaps, struct map *new_map);
if (maps__merge_in(kmaps, new_map)) {