The specification for IntSummaryStatistics.toString is entirely copied from Object.toString:

==========
Description copied from class: Object
Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

     getClass().getName() + '@' + Integer.toHexString(hashCode())
==========

This copies the contract portion of Object.toString's spec, but it shouldn't copy the implementation portion of the specification. Thus, use of @implSpec combined with {@inheritDoc} is called for here. (See JDK-8080449 regarding Object.toString and JDK-8068562 regarding the @implSpec tag.)

In addition, the source code for IntSummaryStatistics.toString has this as its doc comment:

    /**
     * {@inheritDoc}
     *
     * Returns a non-empty string representation of this object suitable for
     * debugging. The exact presentation format is unspecified and may vary
     * between implementations and versions.
     */

For some reason the text "Returns a non-empty string representation..." doesn't appear in the javadoc output. This may be a javadoc bug.

This is probably just one instance of a general problem where overriding methods' specifications should be cleaned up to inherit selectively from their superclass.

Seen on StackOverflow: http://stackoverflow.com/q/30244464/1441122