void (@NotNull PsiAssignmentExpression expression) { super.visitAssignmentExpression(expression); if (expression.getRExpression() == null) return; final PsiJavaToken sign = expression.getOperationSign(); final IElementType tokenType = sign.getTokenType(); if (!tokenType.equals(JavaTokenType.PLUSEQ)) return; if (!checkExpression(expression)) return; PsiExpression lhs = PsiUtil.skipParenthesizedExprDown(expression.getLExpression()); if (!(lhs instanceof PsiReferenceExpression)) return; registerError(sign, expression); }