code: def has_better_coverage(self):
          
          for filename in self.files():
              if self.diff_total_misses(filename) > 0:
                  return False
          return True
docs: Return `True` if coverage of has improved, `False` otherwise.
  
          This does not ensure that all changes have been covered. If this is
          what you want, use `CoberturaDiff.has_all_changes_covered()` instead.