code: @Pure
  	public static <T> T operator_elvis(T first, T second) {
  		if (first != null)
  			return first;
  		return second;
  	}
docs: The elvis operator <code>?:</code> is a short hand notation for
  providing default value in case an expression evaluates to <code>null</code>.
  
  Not that the Xtend compiler will inline calls to this not call this method with a short-circuit semantic.
  That is the second argument is only evaluated if the first one evaluates to <code>null</code>.
  
  Example:
  <code>person.name?:'Hans'</code>
  
  @param first
  an {@link Object}. Might be <code>null</code>.
  @param second
  an {@link Object}. Might be <code>null</code>.
  
  @return a reference to <code>first</code> if <code>first != null </code>, <code>second<code> otherwise,
  @since 2.3