Is there a way to mark a method as pending to implement in Pharo?

Methods whose implementation is still pending should send the notYetImplemented message like this:

methodImNotSureHowToImplement
  ^self notYetImplemented

if the unimplemented message gets sent anyway, it will signal a NotYetImplemented exception which will know the offending selector, #methodImNotSureHowToImplement in my example.

Note also that this will make it easy finding all methods that need to be implemented as senders of #notYetImplemented.

The implementation of #notYetImplemented is straightforward, thanks to the existence of NotYetImplemented.

notYetImplemented
  "Announce that this message is not yet implemented"
   NotYetImplemented signalFor: thisContext sender selector

Note also that NotYetImplemented is one of the subclasses of SelectorException which model several situations of similar kinds:

SelectorException
  NotYetImplemented
  PrimitiveFailed
  ShouldBeImplemented
  ShouldNotImplement
  SubclassResponsibility