options/dag.go
func (dagOpts) Hash(hash string) DagPutOption {
	return func(opts *DagPutSettings) error {
		opts.Hash = hash
		return nil
	}
}
func (dagOpts) Hash(hash string) DagPutOption {
	return func(opts *DagPutSettings) error {
		opts.Hash = hash
		return nil
	}
}
// Hash is an option for Dag.Put which specifies the hash function to use