Widget _toolBar(String headerText){

        return Container(
          decoration: BoxDecoration(
              color: MyColors.greenHeader,
              borderRadius: new BorderRadius.only(
                  bottomLeft: const Radius.circular(15.0),
                  bottomRight: const Radius.circular(15.0))
          ),
          child:Center(child:  Stack(
            children: <Widget>[

              Row(
                mainAxisAlignment: MainAxisAlignment.start,
                mainAxisSize: MainAxisSize.max,
                children: <Widget>[
                  Expanded(
                    flex: 1,
                    child:Text(headerText,
                        textAlign: TextAlign.center,
                        style: TextStyle(
                          color: Colors.white,
                          fontSize: 18.0,
                        )
                    ),),
                ],),

              Row(
                mainAxisAlignment: MainAxisAlignment.start,
                mainAxisSize: MainAxisSize.max,
                children: <Widget>[
                  Flexible(
                    flex: 1,
                    child:IconButton(
                      icon: new Icon(Icons.arrow_back_ios),
                      color: Colors.white,
                      onPressed: (){},
                    )
                    ),
                ],),

            ],
          ),)
        );
    }