docs: private Fix longFix(ExpressionTree expr, VisitorState state) {
      BinaryTree binExpr = null;
      while (expr instanceof BinaryTree) {
        binExpr = (BinaryTree) expr;
        expr = binExpr.getLeftOperand();
      }
      if (!(expr instanceof LiteralTree) || expr.getKind() != Kind.INT_LITERAL) {
        return null;
      }
      Type intType = state.getSymtab().intType;
      if (!isSameType(getType(binExpr), intType, state)) {
        return null;
      }
      SuggestedFix.Builder fix = SuggestedFix.builder().postfixWith(expr, "L");
      Tree parent = state.getPath().getParentPath().getLeaf();
      if (parent instanceof VariableTree && isSameType(getType(parent), intType, state)) {
        fix.replace(((VariableTree) parent).getType(), "long");
      }
      return fix.build();
    }