Clarifies Traversable.min()/max() javadoc. Fixes #1304

javaslang/src/main/java/javaslang/collection/Traversable.java

@@ -630,9 +630,10 @@ default Option<T> lastOption() {
     <U> Traversable<U> map(Function<? super T, ? extends U> mapper);
 
     /**
-     * Calculates the maximum of this elements according to their natural order.
+     * Calculates the maximum of this elements according to the underlying element {@code Comparator} if exists,
+     * or the natural order of elements.
      *
-     * @return {@code Some(maximum)} of this elements or {@code None} if this is empty or this elements are not comparable
+     * @return {@code Some(maximum)} of this elements or {@code None} if this is empty or no {@code Comparator} is applicable
      */
     @SuppressWarnings("unchecked")
     default Option<T> max() {
@@ -690,9 +691,10 @@ default <U extends Comparable<? super U>> Option<T> maxBy(Function<? super T, ?
     }
 
     /**
-     * Calculates the minimum of this elements according to their natural order.
+     * Calculates the minimum of this elements according to the underlying element {@code Comparator} if exists,
+     * or the natural order of elements.
      *
-     * @return {@code Some(minimum)} of this elements or {@code None} if this is empty or this elements are not comparable
+     * @return {@code Some(minimum)} of this elements or {@code None} if this is empty or no {@code Comparator} is applicable
      */
     @SuppressWarnings("unchecked")
     default Option<T> min() {