code: func (c *BoundContract) Transact(opts *TransactOpts, method string, args *Interfaces) (tx *Transaction, _ error) {
  	rawTx, err := c.contract.Transact(&opts.opts, method, args.objects...)
  	if err != nil {
  		return nil, err
  	}
  	return &Transaction{rawTx}, nil
  }
docs: // Transact invokes the (paid) contract method with params as input values.