anchor.diff:  
     TMARSCustomClient = class; // fwd
     TMARSCustomClientClass = class of TMARSCustomClient;
  +
  +  TMARSClientBeforeExecuteProc = reference to procedure (const AURL: string;
  +    const AClient: TMARSCustomClient);
   
     TMARSProxyConfig = class(TPersistent)
     private
  
positive.code:     ApplyProxyConfig;
  end;
  
  constructor TMARSCustomClient.Create(AOwner: TComponent);
  begin
    inherited;
  
negative.code:           LResource.QueryParams.Assign(AQueryParams);
  
          LResource.SpecificToken := AToken;
          FireBeforeExecute(LResource.URL, LClient);
          LResource.GET(nil, nil, nil);
  
          Result := nil;
  