code: public R setPassword(final String password){
          JsonObject jsonObject = getSharedLinkJsonObject();
          jsonObject.add(BoxSharedLink.FIELD_PASSWORD, password);
          BoxSharedLink sharedLink = new BoxSharedLink(jsonObject);
          mBodyMap.put(BoxItem.FIELD_SHARED_LINK, sharedLink);
          return (R) this;
      }
docs: Sets the shared link password in the request.
  
  @param password  new password for the shared link, or null to remove the password.
  @return  request with the updated shared link password.