anchor.diff:    // to be implemented in inherited classes
   end;
   
  +class procedure TMARSCustomClient.FireBeforeExecute(const AURL: string;
  +  const AClient: TMARSCustomClient);
  +var
  +  LProc: TMARSClientBeforeExecuteProc;
  +begin
  +  for LProc in FBeforeExecuteProcs do
  +    LProc(AURL, AClient);
  +end;
  +
   procedure TMARSCustomClient.Get(const AURL: string; AResponseContent: TStream;
     const AAuthToken: string; const AAccept: string; const AContentType: string);
   begin
  
positive.code: 
    TMARSCustomClient = class; // fwd
    TMARSCustomClientClass = class of TMARSCustomClient;
  
    TMARSProxyConfig = class(TPersistent)
    private
  
negative.code:     ApplyProxyConfig;
  end;
  
  class procedure TMARSCustomClient.ClearBeforeExecute;
  begin
    FBeforeExecuteProcs := [];
  end;
  
  constructor TMARSCustomClient.Create(AOwner: TComponent);
  begin
    inherited;
  