Setting Tabs close function
        None -> tabs are not closable

def set_close_function(self, func):
        """Setting Tabs close function
        None -> tabs are not closable"""
        state = func is not None
        if state:
            self.sig_close_tab.connect(func)
        try:
            # Assuming Qt >= 4.5
            QTabWidget.setTabsClosable(self, state)
            self.tabCloseRequested.connect(func)
        except AttributeError:
            # Workaround for Qt < 4.5
            close_button = create_toolbutton(self, triggered=func,
                                             icon=ima.icon('fileclose'),
                                             tip=_("Close current tab"))
            self.setCornerWidget(close_button if state else None)