code: def create(self):
          
          api = self._client.instance_admin_api
          instance_pb = admin_v1_pb2.Instance(
              name=self.name,
              config=self.configuration_name,
              display_name=self.display_name,
              node_count=self.node_count,
          )
          metadata = _metadata_with_prefix(self.name)
  
          future = api.create_instance(
              parent=self._client.project_name,
              instance_id=self.instance_id,
              instance=instance_pb,
              metadata=metadata,
          )
  
          return future
docs: Create this instance.
  
          See
          https://cloud.google.com/spanner/reference/rpc/google.spanner.admin.instance.v1#google.spanner.admin.instance.v1.InstanceAdmin.CreateInstance
  
          .. note::
  
             Uses the ``project`` and ``instance_id`` on the current
             :class:`Instance` in addition to the ``display_name``.
             To change them before creating, reset the values via
  
             .. code:: python
  
                instance.display_name = 'New display name'
                instance.instance_id = 'i-changed-my-mind'
  
             before calling :meth:`create`.
  
          :rtype: :class:`google.api_core.operation.Operation`
          :returns: an operation instance
          :raises Conflict: if the instance already exists