public void initMult(int len, E elem) {
	    checkLength(len);

    	initAll(new IReadOnlyListFromMult<E>(len, elem));
	}
Initializes the list so it will afterwards have a size of
<code>len</code> and contain only the element <code>elem</code>.
The list will grow or shrink as needed.

@param len  	length of list
@param elem 	element which the list will contain
@throws 		IndexOutOfBoundsException if the length is invalid
jphp-runtime/src/php/runtime/memory/support/IList.java