code: public Tuple<Identifier> parseOptionalLifetimeParameters(EnclosingScope scope) {
  		if (tryAndMatch(true, LeftAngle) != null && tryAndMatch(true, RightAngle) == null) {
  			// The if above skips an empty list of identifiers "<>"!
  			return parseLifetimeParameters(scope);
  		}
  		return new Tuple<>();
  	}
docs: Attention: Enters the lifetime names to the passed scope!
  
  @param scope
  @return