code: func (engine *Engine) Join(joinOperator string, tablename interface{}, condition string, args ...interface{}) *Session {
  	session := engine.NewSession()
  	session.isAutoClose = true
  	return session.Join(joinOperator, tablename, condition, args...)
  }
docs: // Join the join_operator should be one of INNER, LEFT OUTER, CROSS etc - this will be prepended to JOIN