code: func NewClient(newHash func() hash.Hash, user, pass string) *Client {
  	c := &Client{
  		newHash: newHash,
  		user:    user,
  		pass:    pass,
  	}
  	c.out.Grow(256)
  	c.authMsg.Grow(256)
  	return c
  }
docs: // NewClient returns a new SCRAM-* client with the provided hash algorithm.
  //
  // For SCRAM-SHA-1, for example, use:
  //
  //    client := scram.NewClient(sha1.New, user, pass)
  //