code: func Detect() (PackageType, error) {
  	for k, v := range execPackagers {
  		_, err := exec.LookPath("/usr/bin/" + v)
  		if err == nil {
  			return PackageType(k), nil
  		}
  	}
  	return -1, errors.New("package manager not found in directory '/usr/bin'")
  }
docs: // Detect tries to get the package system used in the system, looking for
  // executables in directory "/usr/bin".