default int lastIndexOf(final Object element, final int end) {
		return lastIndexOf(element, 0, end);
	}
Returns the index of the last occurrence of the specified element
in this sequence, or -1 if this sequence does not contain the element.

@param element element to search for, can be {@code null}
@param end the search end index
@return the index of the last occurrence of the specified element in
        this sequence, or -1 if this sequence does not contain the element
@throws IndexOutOfBoundsException for an illegal end point index value
         ({@code end < 0 || end > length()}).
jenetics/src/main/java/io/jenetics/util/Seq.java