code: public Conversation createConversation(Member author, String content) {
          Conversation conversation = getInstance().create().conversation(author, content);
          Iterator<Expression> iterator = conversation.getContainedExpressions().iterator();
          iterator.next().getMentions().add(this);
          conversation.save();
          return conversation;
      }
docs: Creates conversation with an expression which mentioned this asset.
  
  @param author Author of conversation expression.
  @param content Content of conversation expression.
  @return Created conversation