docs: protected BinaryExpression findInstanceOfNotReturnExpression(IfStatement ifElse) {
          Statement elseBlock = ifElse.getElseBlock();
          if (!(elseBlock instanceof EmptyStatement)) {
              return null;
          }
          Expression conditionExpression = ifElse.getBooleanExpression().getExpression();
          if (!(conditionExpression instanceof NotExpression)) {
              return null;
          }
          NotExpression notExpression = (NotExpression) conditionExpression;
          Expression expression = notExpression.getExpression();
          if (!(expression instanceof BinaryExpression)) {
              return null;
          }
          BinaryExpression instanceOfExpression = (BinaryExpression) expression;
          int op = instanceOfExpression.getOperation().getType();
          if (op != Types.KEYWORD_INSTANCEOF) {
              return null;
          }
          if (notReturningBlock(ifElse.getIfBlock())) {
              return null;
          }
          return instanceOfExpression;
      }