Suppose I want to implement a functional composition, like this:
public Func Compose(Func f, Func g)
{
The following code would work:
Func toUpper = ToUpper;
Func replicate = Replicate;
// now the compiler knows that the parameters are Func
var h = Compose(toUpper, replicate);
So maybe you can still get the readability improvement you are seeking by defining those variables only once and them reusing them throughout your tests (I'm assuming this is a test utility...)