public boolean addMult(int index, int len, E elem) {
        checkIndexAdd(index);

		return doAddAll(index, new IReadOnlyListFromMult<E>(len, elem));
    }
Inserts element multiple time to list, starting at the specified position.
Shifts the element currently at that position (if any) and any
subsequent elements to the right (increases their indices).

@param index index at which to insert the first element from the
             specified collection
@param elem element to be inserted into this list
@return <tt>true</tt> if this list changed as a result of the call
@throws IndexOutOfBoundsException if the index is invalid
jphp-runtime/src/php/runtime/memory/support/IList.java