code: def instance(self, instance_id, display_name=None, instance_type=None, labels=None):
          
          return Instance(
              instance_id,
              self,
              display_name=display_name,
              instance_type=instance_type,
              labels=labels,
          )
docs: Factory to create a instance associated with this client.
  
          For example:
  
          .. literalinclude:: snippets.py
              :start-after: [START bigtable_create_prod_instance]
              :end-before: [END bigtable_create_prod_instance]
  
          :type instance_id: str
          :param instance_id: The ID of the instance.
  
          :type display_name: str
          :param display_name: (Optional) The display name for the instance in
                               the Cloud Console UI. (Must be between 4 and 30
                               characters.) If this value is not set in the
                               constructor, will fall back to the instance ID.
  
          :type instance_type: int
          :param instance_type: (Optional) The type of the instance.
                                 Possible values are represented
                                 by the following constants:
                                 :data:`google.cloud.bigtable.enums.InstanceType.PRODUCTION`.
                                 :data:`google.cloud.bigtable.enums.InstanceType.DEVELOPMENT`,
                                 Defaults to
                                 :data:`google.cloud.bigtable.enums.InstanceType.UNSPECIFIED`.
  
          :type labels: dict
          :param labels: (Optional) Labels are a flexible and lightweight
                         mechanism for organizing cloud resources into groups
                         that reflect a customer's organizational needs and
                         deployment strategies. They can be used to filter
                         resources and aggregate metrics. Label keys must be
                         between 1 and 63 characters long. Maximum 64 labels can
                         be associated with a given resource. Label values must
                         be between 0 and 63 characters long. Keys and values
                         must both be under 128 bytes.
  
          :rtype: :class:`~google.cloud.bigtable.instance.Instance`
          :returns: an instance owned by this client.