code: public User addProfileImage(long userId, String file, String fileType) throws SmartsheetException, FileNotFoundException {
          return attachProfileImage("users/" + userId + "/profileimage", file, fileType);
      }
docs: Uploads a profile image for the specified user.
  
  @param userId id of the user
  @param file path to the image file
  @param fileType content type of the image file
  @return user
  @throws IllegalArgumentException if any argument is null or empty string
  @throws InvalidRequestException if there is any problem with the REST API request
  @throws AuthorizationException if there is any problem with  the REST API authorization (access token)
  @throws ResourceNotFoundException if the resource cannot be found
  @throws ServiceUnavailableException if the REST API service is not available (possibly due to rate limiting)
  @throws SmartsheetException f there is any other error during the operation