anchor.diff:  
     Commit(this.github);
   
  +  Map<String, dynamic> json;
  +  
     static Commit fromJSON(GitHub github, input) {
       var commit = new Commit(github)
           ..url = input['html_url']
  
positive.code:    * Commit SHA
     */
    String sha;
  
    /**
     * Commit Message
  
negative.code:         ..authoredAt = parseDateTime(input['commit']['author']['date'])
          ..committedAt = parseDateTime(input['commit']['committer']['date'])
          ..committerEmail = input['commit']['committer']['email']
          ..authorEmail = input['commit']['author']['email']
          ..treeSha = input['tree']['sha'];
  
      commit.json = input;
      
      if (input['stats'] != null) {
        commit
            ..additionsCount = input['stats']['additions']
  