In the sole caller of `G1Policy::calculate_desired_eden_length_by_mmu`:
```
if (use_adaptive_young_list_length()) {
desired_eden_length_by_mmu = calculate_desired_eden_length_by_mmu();
```
so, one can assert `use_adaptive_young_list_length()` as a precondition, instead of checking for it again.
```
if (use_adaptive_young_list_length()) {
desired_eden_length_by_mmu = calculate_desired_eden_length_by_mmu();
```
so, one can assert `use_adaptive_young_list_length()` as a precondition, instead of checking for it again.