NUnit.Mocks was originally developed for internal use in NUnit's own tests, although we no longer use it for that purpose.
In addition, it has been useful as a teaching tool, allowing users to gain familiarity with mocking techniques before moving on to more serious frameworks.
For production use, we recommend you install a full-featured mock object framework.
The NUnit project now uses NSubstitute and NUnit.Mocks is no longer being developed.
Install-Package NUnit.Mocks -Version 2.6.4
dotnet add package NUnit.Mocks --version 2.6.4
<PackageReference Include="NUnit.Mocks" Version="2.6.4" />
paket add NUnit.Mocks --version 2.6.4