anchor.diff:  import "package:googleapis/common/common.dart" as common_external;
   import "package:http_base/http_base.dart" as http_base;
   
  -const CONTENT_TYPE_UTF8 = 'application/json; charset=utf-8';
  +const CONTENT_TYPE_JSON_UTF8 = 'application/json; charset=utf-8';
   
   class HeadersImpl implements http_base.Headers {
     final Map<String, List<String>> _m = {};
  
positive.code:       var headers;
        if (downloadRange != null) {
          headers = new HeadersImpl({
            'content-type' : [CONTENT_TYPE_UTF8],
            'content-length' : ['$length'],
            'range' : [
                'bytes=${downloadRange.start}-${downloadRange.end}',
  
negative.code:     });
    }
  
    Future _request(String requestUrl, String method,
                    String body, Map urlParams, Map queryParams,
                    common_external.Media uploadMedia,
  