anchor.diff:  ///
   /// The implied getter and setter for the field are not represented explicitly,
   /// but can be made explicit if needed.
  -class Field extends Member implements FileUriNode {
  +class Field extends Member {
     DartType type; // Not null. Defaults to DynamicType.
     int flags = 0;
     int flags2 = 0;
     Expression initializer; // May be null.
  -
  -  /// The uri of the source file this field was loaded from.
  -  Uri fileUri;
   
     Field(Name name,
         {this.type: const DynamicType(),
  
positive.code:   /// If the URI has the `app` scheme, it is relative to the application root.
    Uri importUri;
  
    /// The uri of the source file this library was loaded from.
    Uri fileUri;
  
    /// If true, the library is part of another build unit and its contents
  
negative.code: // ------------------------------------------------------------------------
  
  @coq
  abstract class Member extends NamedNode implements FileUriNode {
    /// End offset in the source file it comes from. Valid values are from 0 and
    /// up, or -1 ([TreeNode.noOffset]) if the file end offset is not available
    /// (this is the default if none is specifically set).
  