How to hide a Tab Bar in Maya docked window?

I want to hide the tab bar when docking a window made of Maya workspacecontrol.

What I want is to be able to select and move to a dotted line like Maya's shelf window.

I am testing with the code below.

import maya.cmds as cmds

def createCustomWorkspaceControlUI(*args):
  cmds.columnLayout()
  cmds.button()
  cmds.button()
  cmds.button()

cmds.workspaceControl("myCustomWorkspaceControl", retain=False, floating=True, uiScript="createCustomWorkspaceControlUI()");