How to delete the Kong workspace+how to delete an empty workspace of kong+cannot delete an empty workspace

When we try to delete a workspace, an error is occurred as below then some of roles and files are available, we should remove/delete those files and roles then it is possible to delete the same.

First:
Team –> Roles (tabs) –> select the appropriate workspace
    – display the default role : you should delete those roles
Second:
click the menu Workspace –> select the appropriate workspace –> Dev Portal –> Editor
    – delete all those files which are listed left side menu
    – folder delete option won’t work, should have a patient to delete those files

then edit workspace –> then “delete” it should possible to delete the workspace

When creating a Workspace, four default Roles are added automatically.

If you delete these system generated roles, then edit the workspace and delete the workspace.