public void GivenNeverExecutedWhenCanExecuteCalledThenShouldBeTrue()
        {
            var target = new RunOnceCommand(() => { });

            Assert.IsTrue(
                target.CanExecute(null),
                "Test failed: can execute should return true when command has not been executed.");
        }
        public void GivenExecutedOnceWhenCanExecuteCalledThenShouldBeFalse()
        {
            var target = new RunOnceCommand(() => { });

            target.Execute(null);
            Assert.IsFalse(
                target.CanExecute(null),
                "Test failed: can execute should return false when command has been executed.");
        }