c# list add if not matches code example
Example: c# verify in class exist in list
Item wonderIfItsPresent = ...
bool containsItem = myList.Any(item => item.UniqueProperty == wonderIfItsPresent.UniqueProperty);'
Item wonderIfItsPresent = ...
bool containsItem = myList.Any(item => item.UniqueProperty == wonderIfItsPresent.UniqueProperty);'