code: def enrollment_start(
              self,
              name,
              mode=None,
              pin=None,
              phone_number=None
      ):
          
          data = {
              "name": name,
          }
  
          if mode:
              warning_msg = 'WARNING: The "mode" parameter for enrollment_start is DEPRECATED and will be ignored. ' \
                            'To avoid incompatibility with a future release please stop providing it.'
              print(warning_msg, file=sys.stderr)
          if pin:
              data["pin"] = pin
          if phone_number:
              data["phone_number"] = phone_number
  
          response = self._post(url.enrollments, body=data)
          self._check_response(response, 201)
          return self._create_response(response)
docs: Start Client Enrollment.  Uses the POST to /enrollments interface.
  
          :Args:
              * *client*: (str) Client's Name
              * *mode*: (str) DEPRECATED. Presence of PIN is used to determine mode (AudioPass vs AudioPIN)
              * *pin*: (str) Client's PIN. 4 digit string
              * *phone_number*: (str) Phone number to call.
  
          :Returns: (dict) Enrollment record with prompts as described `here <https://cloud.knuverse.com/docs/api/#api-Enrollments-Start_enrollment>`_.