code: def create(self):
          
          api = self._instance._client.database_admin_api
          metadata = _metadata_with_prefix(self.name)
          db_name = self.database_id
          if "-" in db_name:
              db_name = "`%s`" % (db_name,)
  
          future = api.create_database(
              parent=self._instance.name,
              create_statement="CREATE DATABASE %s" % (db_name,),
              extra_statements=list(self._ddl_statements),
              metadata=metadata,
          )
          return future
docs: Create this database within its instance
  
          Inclues any configured schema assigned to :attr:`ddl_statements`.
  
          See
          https://cloud.google.com/spanner/reference/rpc/google.spanner.admin.database.v1#google.spanner.admin.database.v1.DatabaseAdmin.CreateDatabase
  
          :rtype: :class:`~google.api_core.operation.Operation`
          :returns: a future used to poll the status of the create request
          :raises Conflict: if the database already exists
          :raises NotFound: if the instance owning the database does not exist