code: func BuildPluginCommandString(pluginType, pluginName string) (string, error) {
  	terraformPath, err := osext.Executable()
  	if err != nil {
  		return "", err
  	}
  	parts := []string{terraformPath, "internal-plugin", pluginType, pluginName}
  	return strings.Join(parts, TFSPACE), nil
  }
docs: // BuildPluginCommandString builds a special string for executing internal
  // plugins. It has the following format:
  //
  // 	/path/to/terraform-TFSPACE-internal-plugin-TFSPACE-terraform-provider-aws
  //
  // We split the string on -TFSPACE- to build the command executor. The reason we
  // use -TFSPACE- is so we can support spaces in the /path/to/terraform part.