How to run parallel tests with C#-xUnit?

How to run parallel tests with C#-xUnit?

For xUnit – Parallelism by putting the test classes into a single test collection or by executing an ‘n’ number of threads in parallel. [assembly: CollectionBehavior(CollectionBehavior.CollectionPerAssembly)] [assembly: CollectionBehavior(MaxParallelThreads = n)]

Sample code snippet:

[assembly: CollectionBehavior(MaxParallelThreads = 4)]

public class UnitTest_1 : IClassFixture<ParallelLTTests>
{
        [Theory]
        [InlineData("chrome", "72.0", "Windows 10")]
        [InlineData("MicrosoftEdge", "18.0", "Windows 10")]
        [InlineData("Firefox", "70.0", "Windows 10")]
        [InlineData("Safari", "12.0", "macOS Mojave")]

public void LT_ToDo_Test(String browser, String version, String os)