code: @Override
  	public boolean contains(Object elem) {
  		if (elem == null) return false;
  		if (elem instanceof Number) return contains(((Number)elem).longValue());
  		return false;
  	}
docs: Returns <tt>true</tt> if this list contains the specified element.
  
  @param elem element whose presence in this List is to be tested.
  @return  <code>true</code> if the specified element is present;
  <code>false</code> otherwise.