code: func (mod *Module) Compare(other *Module) int {
  	if mod == nil {
  		if other == nil {
  			return 0
  		}
  		return -1
  	} else if other == nil {
  		return 1
  	}
  	if cmp := mod.Package.Compare(other.Package); cmp != 0 {
  		return cmp
  	}
  	if cmp := importsCompare(mod.Imports, other.Imports); cmp != 0 {
  		return cmp
  	}
  	return rulesCompare(mod.Rules, other.Rules)
  }
docs: // Compare returns an integer indicating whether mod is less than, equal to,
  // or greater than other.