code: def type(self):
          
          if self._device_mode == 1 or self._type == CertificateType.developer:
              return CertificateType.developer
          elif self._type == CertificateType.bootstrap:
              return CertificateType.bootstrap
          else:
              return CertificateType.lwm2m
docs: Certificate type.
  
          :return: The type of the certificate.
          :rtype: CertificateType