anchor.diff:    bool get isPositional;
   
     /// Return `true` if this parameter is both a required and named parameter.
  +  /// Named parameters that are annotated with the `@required` annotation are
  +  /// considered optional.  Named parameters that are annotated with the
  +  /// `required` syntax are considered required.
     bool get isRequiredNamed;
   
     /// Return `true` if this parameter is both a required and positional
  
positive.code:   bool get isNotOptional;
  
    /// Return `true` if this parameter is an optional parameter. Optional
    /// parameters can either be positional or named.
    bool get isOptional;
  
    /// Return `true` if this parameter is both an optional and named parameter.
    bool get isOptionalNamed;
  
    /// Return `true` if this parameter is both an optional and positional
  
negative.code:   /// Return `true` if this parameter is an initializing formal parameter.
    bool get isInitializingFormal;
  
    /// Return `true` if this parameter is a named parameter. Named parameters
    /// that are annotated with the `@required` annotation are considered
    /// optional.  Named parameters that are annotated with the `required` syntax
    /// are considered required.
    bool get isNamed;
  
    /// Return `true` if this parameter is a required parameter. Required
  