code: @Nonnull
      protected Set<OWLAnnotation> mergeAnnos(Set<OWLAnnotation> annos) {
          Set<OWLAnnotation> merged = new HashSet<>(annos);
          merged.addAll(annotations);
          return merged;
      }
docs: A convenience method for implementation that returns a set containing the
  annotations on this axiom plus the annotations in the specified set.
  
  @param annos
  The annotations to add to the annotations on this axiom
  @return The annotations