code: func (p ProviderInstance) Alias() string {
  	t := string(p)
  	if dotPos := strings.Index(t, "."); dotPos != -1 {
  		return t[dotPos+1:]
  	}
  	return ""
  }
docs: // Alias returns the alias of this provider, if any. An instance named "aws.foo"
  // has the alias "foo", while an instance named just "docker" has no alias,
  // so the empty string would be returned.