Parameters
- key
 - The key of the item.
 
Return Value
True - the data storage contains an item with the specified key; false - the data storage does NOT contain an item with the specified key.
        | Исключение | Описание | 
|---|---|
| System.ArgumentNullException | Thrown if key is null or empty. | 
Целевые платформы: .NET 9; .NET 8; .NET 7; .NET 6; .NET Framework 4.8, 4.7, 4.6, 4.5, 4.0, 3.5