Container(
                  child: ListTile(
                    title: Text("Category :-"),
                    subtitle: DropdownButtonFormField<Service>(
                      value: _category,
                      items: List.generate(
                        snapshot.data.length,
                        (index) => DropdownMenuItem<Service>(
                          child: Text(snapshot.data[index].name),
                          value: snapshot.data[index],
                        ),
                      ),
                      hint: Text("Choose.."),
                      onChanged: (value) {
                        setState(() {
                          _category = value;
                        });
                      },
                    ),
                  ),
                ),
                //TODO:- need to work on it

                Container(
                  child: ListTile(
                    title: Text("Service :-"),
                    subtitle: (_category != null)
                        ? DropdownButtonFormField<SubService>(
                            value: _service,
                            items: List.generate(
                              _category.childs.length,
                              (index) => DropdownMenuItem<SubService>(
                                child: Text(_category.childs[index].name),
                                value: _category.childs[index],
                              ),
                            ),
                            hint: Text("Choose.."),
                            onChanged: (value) {
                              setState(() {
                                _service = value;
                              });
                            },
                          )
                        : Text(
                            "Choose a category first!",
                            style: TextStyle(
                              color: Colors.red,
                            ),
                          ),
                  ),
                ),