@Override
    public int compare(final E obj1, final E obj2) {
        return obj1.compareTo(obj2);
    }
Compare the two {@link Comparable Comparable} arguments.
This method is equivalent to:
<pre>((Comparable)obj1).compareTo(obj2)</pre>

@param obj1  the first object to compare
@param obj2  the second object to compare
@return negative if obj1 is less, positive if greater, zero if equal
@throws NullPointerException if <i>obj1</i> is <code>null</code>,
        or when <code>((Comparable)obj1).compareTo(obj2)</code> does
@throws ClassCastException if <i>obj1</i> is not a <code>Comparable</code>,
        or when <code>((Comparable)obj1).compareTo(obj2)</code> does
ttl2-compatible/src/main/java/com/alibaba/ttl/threadpool/ComparableComparator.java