Verify.cs

[Fact]
public void Verify()
{
    var mock = new Mock<IPropertyManager>();
    var nameUser = new PropertyManagerConsumer(mock.Object);

    nameUser.ChangeRemoteName("My dear old wig");

    //we are verifying that ChangeRemoteName sends the correct string to MutateFirstName
    mock.Verify(m => m.MutateFirstName(It.Is<string>(a => a == "My dear old wig")), Times.Once);
}