anchor.diff:            "foo/": "%http/packages/foo/",
             "foo/bar": "%http/packages/foo/bar",
             "foo.x": null,
  +          "bar/bar": "%http/packages/bar/bar",
           });
       }
   
  
positive.code: // * `Process.packageConfig`
  // * `Isolate.packageRoot`
  // * `Isolate.packageRoot`
  // * `Isolate.resolvePacakgeUri` of various inputs.
  // * A variable defined in a library loaded using a `package:` URI.
  //
  // The configurations all have URIs as `root`, `config` and `mainFile` strings,
  
negative.code:           "foo/": "%http/sub/packages/foo/",
            "foo/bar": "%http/sub/packages/foo/bar",
            "foo.x": null,
            "bar/bar": "%http/sub/packages/bar/bar",
          });
      }
  
  