docs: public static MutableLong fromExternal(final LongSupplier s, final LongConsumer c) {
          return new MutableLong() {
              @Override
              public long getAsLong() {
                  return s.getAsLong();
              }
  
              @Override
              public Long get() {
                  return getAsLong();
              }
  
              @Override
              public MutableLong set(final long value) {
                  c.accept(value);
                  return this;
              }
          };
      }