How should I inherit IDisposable?

Question

Class names have been changed to protect the innocent.

If I have an interface named ISomeInterface. I also have classes that inherit the interface, FirstClass

Answer 1

If there is a reasonable chance that an abstract entity (interface or abstract class) might need to be disposable, it should implement it. Stream, for example doesn't itself need IDisposable, nor does IEnumerator...

An abstract base class may be simpler, as you can have a default (empty) implementation of Dispose() then, and possibly the finalizer / Dispose(bool) pattern, i.e.

void IDisposable.Dispose() { Dispose(true); GC.SuppressFinalize(this); }
protected virtual void Dispose(bool disposing) {}
~BaseType() {Dispose(false);}