new_contents: def sign_request(params, url, method, consumer, secret):
      pass
  
  def check_params(params):
      if LTI_VERSION not in params:
          params[LTI_VERSION] = LTI_VERSION_1
  
      if LTI_MESSAGE_TYPE not in params:
          params[LTI_MESSAGE_TYPE] = LTI_MESSAGE_TYPE_BASICLTILAUNCHREQUEST
  
      if BASICLTI_SUBMIT not in params:
          params[BASICLTI_SUBMIT] = ""
  
      #any non-standard param should be converted to ext_param or custom_param
  
      
  
subject: add lti oauth functions file (wip)