public int indexOf(Object elem, int fromIndex) {
		if (fromIndex < 0) {
			fromIndex = 0;
		}
		int size = size();
		for (int i=fromIndex; i<size; i++) {
			if (equalsElem(doGet(i), elem)) {
				return i;
			}
		}
		return -1;
	}
Returns the index of the first occurrence of the specified element in this list, starting the search at the specified position.
If the element is not found, -1 is returned.

@param elem			element to search for
@param fromIndex		start index for search
@return				the index of the first occurrence of the specified element in this list that is greater than or equal to fromIndex,
						or -1 if this list does not contain the element
@see #indexOf(Object)
jphp-runtime/src/php/runtime/memory/support/IList.java