0-1-8. Exception: empty interface function.

[banhamd]

Since you have to provide an implementation for an interface, even when it has null operations, you have no choice. Whether this rule should just apply to plain functions and not to class method functions is not clear, but an obvious solution. The introduction to the set of rules that this one belongs to, in section 6.0.1, sets out a clear intent that in the case of interfaces should be directed at the interface design and not specifically at uses of it resulting in null operations.