>>24,25 を Squeak Smalltalk で意訳してみました。#subclassResponsibilityなメソッドが未再定義だと警告。

Trait named: #TShouldBeDefinedAlert

TShouldBeDefinedAlert classTrait >> new
　 | shouldBeDefined |
　 shouldBeDefined := (self allSelectors
　 detect: [:sel | (self lookupSelector: sel) messages includes: #subclassResponsibility]
　 ifNone: [^super new]).
　 self error: shouldBeDefined printString, ' should be defined'


Object subclass: #AbstractMyClass
　 uses: TShouldBeDefinedAlert

AbstractMyClass >> hoge
　 self subclassResponsibility

AbstractMyClass >> fuga
　 self subclassResponsibility


AbstractMyClass subclass: #MyClass

MyClass >> hoge
　 ^#something

- - - - - - - - - - - - - - - - -

MyClass new "=> Error: #fuga should be defined"