code: func (ac *PolicyBasedAccessControl) checkExpectation(plainExpectation *token.PlainExpectation, signedData []*common.SignedData, c *token.Command) error {
  	switch t := plainExpectation.GetPayload().(type) {
  	case *token.PlainExpectation_ImportExpectation:
  		return ac.ACLProvider.CheckACL(
  			ac.ACLResources.IssueTokens,
  			c.Header.ChannelId,
  			signedData,
  		)
  	case *token.PlainExpectation_TransferExpectation:
  		return ac.ACLProvider.CheckACL(
  			ac.ACLResources.TransferTokens,
  			c.Header.ChannelId,
  			signedData,
  		)
  	default:
  		return errors.Errorf("expectation payload type not recognized: %T", t)
  	}
  }
docs: // checkExpectation checks either issue policy or transfer policy depending on the payload type in expectation