code: func (b *backendInstance) CooperativeClose(opts *bind.TransactOpts,
  	agent common.Address, block uint32, offeringHash [common.HashLength]byte,
  	balance uint64, balanceSig, closingSig []byte) (*types.Transaction, error) {
  	ctx2, cancel := b.addTimeout(opts.Context)
  	defer cancel()
  
  	opts.Context = ctx2
  
  	tx, err := b.psc.CooperativeClose(opts, agent, block, offeringHash,
  		balance, balanceSig, closingSig)
  	if err != nil {
  		return nil, fmt.Errorf("failed to do cooperative close: %s", err)
  	}
  	return tx, nil
  }
docs: // CooperativeClose calls cooperativeClose method of Privatix service contract.