void (@NotNull PsiPrefixExpression expression) { super.visitPrefixExpression(expression); if (!isUnaryNegation(expression)) { return; } final PsiExpression operand = expression.getOperand(); if (!isNegation(operand)) { return; } PsiExpression nestedOperand = PsiUtil.skipParenthesizedExprDown(operand); if (nestedOperand instanceof PsiPrefixExpression) { PsiExpression nestedPrefixOperand = ((PsiPrefixExpression)nestedOperand).getOperand(); if (nestedPrefixOperand == null || !LambdaUtil.isSafeLambdaReturnValueReplacement(expression, nestedPrefixOperand)) { return; } } registerError(expression); }