MSTest setup/teardown methods that run before and after ALL tests

Question

Relatively new to MSTest v2 in Visual Studio 2019. The TestInitialize attribute indicates the method should run before each and every test. Similarly, TestCleanup indicates the method should run after each and every test.

[TestInitialize()]
public void Setup()
{
    // This method will be called before each MSTest test method
}

[TestCleanup()]
public void Teardown()
{
    // This method will be called after each MSTest test method has completed
}

If your test class has N methods, the above methods will run N times.

Is there a way to signal setup and teardown-like methods that run once only? In other words, for each complete run through all N tests, each method will run once only.

Are there similar mechanisms for NUnit3 and xUnit v2.4.0?