How to tell if TypeWriter Parameter Type is an Interface

Question

How would you be able to tell if the parameter retrieved from a method is itself an interface?

These attempts below does not seem to work:

 method.Parameters.Select(p => p.Type.Interfaces)
 method.Parameters.Select(p => p.Type.NestedInterfaces)
 method.Type.Interfaces

Why isn't there an .IsInterface on the TypeWriter Type? You can call .IsEnum but no .IsInterface