docs: public static CompoundAssignment compoundAssignment(
        Kind operator,
        Matcher<ExpressionTree> leftOperandMatcher,
        Matcher<ExpressionTree> rightOperandMatcher) {
      Set<Kind> operators = new HashSet<>(1);
      operators.add(operator);
      return new CompoundAssignment(operators, leftOperandMatcher, rightOperandMatcher);
    }