code: public static <T, A, D> Collector<T, ?, D> minAll(Comparator<? super T> comparator, Collector<T, A, D> downstream) {
          return maxAll(Fn.reversedOrder(comparator), downstream);
      }
docs: It's copied from StreamEx: https://github.com/amaembo/streamex under Apache License v2 and may be modified.
  <br />
  
  Returns a {@code Collector} which finds all the elements which are equal
  to each other and smaller than any other element according to the
  specified {@link Comparator}. The found elements are reduced using the
  specified downstream {@code Collector}.
  
  @param <T> the type of the input elements
  @param <A> the intermediate accumulation type of the downstream collector
  @param <D> the result type of the downstream reduction
  @param comparator a {@code Comparator} to compare the elements
  @param downstream a {@code Collector} implementing the downstream
  reduction
  @return a {@code Collector} which finds all the minimal elements.
  @see #minAll(Comparator)
  @see #minAll(Collector)
  @see #minAll()