code: def _create_user_posts_table(self):
          
          with self._engine.begin() as conn:
              user_posts_table_name = self._table_name("user_posts")
              if not conn.dialect.has_table(conn, user_posts_table_name):
                  post_id_key = self._table_name("post") + ".id"
                  self._user_posts_table = sqla.Table(
                      user_posts_table_name, self._metadata,
                      sqla.Column("user_id", sqla.String(128), index=True),
                      sqla.Column("post_id", sqla.Integer,
                                  sqla.ForeignKey(post_id_key,
                                                  onupdate="CASCADE",
                                                  ondelete="CASCADE"),
                                  index=True),
                      sqla.UniqueConstraint('user_id', 'post_id', name='uix_2'),
                      info=self._info
                  )
                  self._logger.debug("Created table with table name %s" %
                                     user_posts_table_name)
              else:
                  self._user_posts_table = \
                      self._metadata.tables[user_posts_table_name]
                  self._logger.debug("Reflecting to table with table name %s" %
                                     user_posts_table_name)
docs: Creates the table to store association info between user and blog
          posts.
          :return: