anchor.diff:      }
     }
     ''';
  -
  -  final _query_pullRequests = 
  -  r'''
  -  query { 
  -    repository(owner:"${repositoryOwner}", name:"${repositoryName}") {
  -      pullRequests(first: 25, 
  -        after: ${after}, 
  -        ${states})
  -      {
  -        totalCount,
  -        pageInfo ${pageInfoResponse}
  -        edges {
  -          node ${pullRequestResponse}
  -        }
  -      }
  -    }
  -  }
  -  ''';
  -
   }
   
   class _PageInfo {
  
positive.code: 
        return Issue.fromGraphQL(page.data['repository']['issue']);
    }
  
    Future<List<Issue>> issues({String owner, String name, String filterSpec = null}) async {
      var filter = filterSpec == null ? '' : 
      '''
      filterBy: {
                ${filterSpec}
              }
      ''';
     
      var result = List<Issue>();
      var done = false;
      var after = 'null';
      do {
        var query = _query_issues
          .replaceAll(r'${repositoryOwner}', owner)
          .replaceAll(r'${repositoryName}', name)
          .replaceAll(r'${after}', after)
          .replaceAll(r'${filter}', filter)
          .replaceAll(r'${issueResponse}', Issue.jqueryResponse)
          .replaceAll(r'${pageInfoResponse}', _PageInfo.jqueryResponse);
  
        final options = QueryOptions(document: query);
  
        final page = await _client.query(options);
  
        if (page.hasErrors) {
          throw(page.errors.toString());
        }
  
        var edges = page.data['repository']['issues']['edges'];
        edges.forEach((edge) {
          var issue = Issue.fromGraphQL(edge['node']);
          result.add(issue);
        });
   
        _PageInfo pageInfo = _PageInfo.fromGraphQL(page.data['repository']['issues']['pageInfo']);
  
        done = !pageInfo.hasNextPage;
        if (!done) after = '"${pageInfo.endCursor}"';
  
      } while( !done );
  
      return result;
    }
    
  
    Future<PullRequest> pullRequest({String owner, String name, int number}) async {
      var query = _query_pullRequest
        .replaceAll(r'${repositoryOwner}', owner)
  
negative.code:   }
    ''';
  
    final _query_pullRequest = 
    r'''
    query { 
  