anchor.diff:    final bool isFinal;
   }
   
  +/**
  + * A [ParameterMirror] reflects a Dart formal parameter declaration.
  + */
  +interface ParameterMirror extends VariableMirror {
  +  /**
  +   * Returns the type of this parameter.
  +   */
  +  final TypeMirror type;
  +
  +  /**
  +   * Returns the default value for this parameter.
  +   */
  +  final String defaultValue;
  +
  +  /**
  +   * Returns true if this parameter has a default value.
  +   */
  +  final bool hasDefaultValue;
  +
  +  /**
  +   * Returns true if this parameter is optional.
  +   */
  +  final bool isOptional;
  +}
   
   /**
    * When an error occurs during the mirrored execution of code, a
  
positive.code: }
  
  /**
   * A [ParameterMirror] reflects a Dart formal parameter declaration.
   */
  interface ParameterMirror extends VariableMirror {
    /**
     * Returns the type of this parameter.
     */
    final TypeMirror type;
  
    /**
     * Returns the default value for this parameter.
     */
    final String defaultValue;
  
    /**
     * Returns true if this parameter has a default value.
     */
    final bool hasDefaultValue;
  
    /**
     * Returns true if this parameter is optional.
     */
    final bool isOptional;
  }
  
  /**
   * A [VariableMirror] reflects a Dart language variable declaration.
   */
  interface VariableMirror {
  
negative.code: }
  
  /**
   * A [LibraryMirror] reflects a Dart language library, providing
   * access to the variables, functions, classes, and interfaces of the
   * library.
   */
  interface LibraryMirror extends ObjectMirror {
    /**
     * The name of this library, as provided in the [#library] declaration.
     */
    final String simpleName;
  
    /**
     * The url of the library.
     *
     * TODO(turnidge): Document where this url comes from.  Will this
     * value be sensible?
     */
    final String url;
  
    /**
     * An immutable map from from names to mirrors for all members in
     * this library.
     *
     * The members of a library are its top-level classes, interfaces,
     * functions, variables, getters, and setters.
     */
    final Map<String, Mirror> members;
  
    /**
     * An immutable map from names to mirrors for all class and
     * interface declarations in this library.
     */
    final Map<String, ClassMirror> classes;
  
    /**
     * An immutable map from names to mirrors for all function
     * declarations in this library.
     */
    final Map<String, MethodMirror> functions;
  
    /**
     * An immutable map from names to mirrors for all variable
     * declarations in this library.
     */
    final Map<String, VariableMirror> variables;
  }
  
  /**
   * A [TypeMirror] reflects a Dart language class, interface, typedef
   * or type variable.
   */
  