how to change window devtool bounds x, y, width, height

[reslear]

Used to do so

let devtools = new BrowserWindow({
      frame : false,
      parent : mainWindow,
      skipTaskbar : true,
});      

devtools.setMenuBarVisibility(false);
mainWindow.webContents.setDevToolsWebContents(devtools.webContents);
mainWindow.webContents.openDevTools({ mode: 'detach' })

mainWindow.webContents.once('did-finish-load', function () {
      let windowBounds = mainWindow.getBounds();
      devtools.setPosition(windowBounds.x + windowBounds.width, windowBounds.y);
      devtools.setSize(windowBounds.width/2, windowBounds.height);
});

mainWindow.on('move', function () {
      let windowBounds = mainWindow.getBounds();
      devtools.setPosition(windowBounds.x + windowBounds.width, windowBounds.y);   
});

how to do with a electron-debug ?