code: def app_profile(
          self,
          app_profile_id,
          routing_policy_type=None,
          description=None,
          cluster_id=None,
          allow_transactional_writes=None,
      ):
          
          return AppProfile(
              app_profile_id,
              self,
              routing_policy_type=routing_policy_type,
              description=description,
              cluster_id=cluster_id,
              allow_transactional_writes=allow_transactional_writes,
          )
docs: Factory to create AppProfile associated with this instance.
  
          For example:
  
          .. literalinclude:: snippets.py
              :start-after: [START bigtable_create_app_profile]
              :end-before: [END bigtable_create_app_profile]
  
          :type app_profile_id: str
          :param app_profile_id: The ID of the AppProfile. Must be of the form
                                 ``[_a-zA-Z0-9][-_.a-zA-Z0-9]*``.
  
          :type: routing_policy_type: int
          :param: routing_policy_type: The type of the routing policy.
                                       Possible values are represented
                                       by the following constants:
                                       :data:`google.cloud.bigtable.enums.RoutingPolicyType.ANY`
                                       :data:`google.cloud.bigtable.enums.RoutingPolicyType.SINGLE`
  
          :type: description: str
          :param: description: (Optional) Long form description of the use
                               case for this AppProfile.
  
          :type: cluster_id: str
          :param: cluster_id: (Optional) Unique cluster_id which is only required
                              when routing_policy_type is
                              ROUTING_POLICY_TYPE_SINGLE.
  
          :type: allow_transactional_writes: bool
          :param: allow_transactional_writes: (Optional) If true, allow
                                              transactional writes for
                                              ROUTING_POLICY_TYPE_SINGLE.
  
          :rtype: :class:`~google.cloud.bigtable.app_profile.AppProfile>`
          :returns: AppProfile for this instance.