docs: public void setExtends(String superType) {
  		if (!Strings.isEmpty(superType)
  				&& !Skill.class.getName().equals(superType)) {
  			JvmParameterizedTypeReference superTypeRef = newTypeRef(this.sarlSkill, superType);
  			JvmTypeReference baseTypeRef = findType(this.sarlSkill, Skill.class.getCanonicalName());
  			if (isSubTypeOf(this.sarlSkill, superTypeRef, baseTypeRef)) {
  				this.sarlSkill.setExtends(superTypeRef);
  				return;
  			}
  		}
  		this.sarlSkill.setExtends(null);
  	}