code: def verification_start(
          self,
          client,
          mode=None,
          verification_speed=None,
          row_doubling="off",
          phone_number=None,
      ):
          
  
          data = {
              "name": client,
              "user_agent": "knuverse-sdk-python-v%s" % self.version
          }
          if mode:
              data["mode"] = mode
  
          if phone_number:
              data["phone_number"] = phone_number
  
          if verification_speed:
              data["verification_speed"] = verification_speed
  
          if row_doubling:
              data["row_doubling"] = row_doubling
  
          response = self._post(url.verifications, body=data)
          self._check_response(response, 201)
          return self._create_response(response)
docs: Start a verification.  Uses POST to /verifications interface.
  
          :Args:
              * *client*: (str) Client's Name
              * *mode*: (str) Verification Mode. Allowed values: "audiopin", "audiopass"
              * *verification_speed*: (int) Allowed values: 0, 25, 50, 75, 100
              * *row_doubling*: (str) Allowed values: "off", "train", "on"
              * *phone_number*: (str) Phone number to call.
  
          :Returns: (dict) Verification record with animation as discussed `here <https://cloud.knuverse.com/docs/api/#api-Verifications-Start_verification>`_.