default int binarySearch(T key){
  return Collections.binarySearch((List<? extends Comparable<? super T>>)this,key);
}

default int binarySearch ( T key ) { return Collections . binarySearch ( ( List < ? extends Comparable < ? super T > > ) this , key ) ; }
searches for the specified object using the binary search algorithm . the elements in this list must implement comparable and the list must be sorted into ascending order .
