<PackageReference Include="NUnit" Version="3.5.0" />

Does

public static class Does
Helper class with properties and methods that supply a number of constraints used in Asserts.
using NUnit.Framework.Constraints; namespace NUnit.Framework { public static class Does { public static ConstraintExpression Not => new ConstraintExpression().Not; public static FileOrDirectoryExistsConstraint Exist => new FileOrDirectoryExistsConstraint(); public static CollectionContainsConstraint Contain(object expected) { return new CollectionContainsConstraint(expected); } public static ContainsConstraint Contain(string expected) { return new ContainsConstraint(expected); } public static StartsWithConstraint StartWith(string expected) { return new StartsWithConstraint(expected); } public static EndsWithConstraint EndWith(string expected) { return new EndsWithConstraint(expected); } public static RegexConstraint Match(string pattern) { return new RegexConstraint(pattern); } } }