code: public Collection<Message> getAll() {
          final int firstMessagePosition = this.getFirstPosition();
          if (firstMessagePosition < MessageStore.INITIAL_MESSAGE_POSITION) {
              return Collections.unmodifiableList(Collections.emptyList());
          }
          return this.getFrom(firstMessagePosition);
      }
docs: Return all messages currently present.
  
  @return Unmodifiable list containing those messages.