def close_tab(self,current_tab):
        """ Called when you need to try to close a tab.

        It takes the number of the tab to be closed as argument, or a reference
        to the widget inside this tab
        """

        # let's be sure "tab" and "closing widget" are respectively the index
        # of the tab to close and a reference to the frontend to close
        if type(current_tab) is not int :
            current_tab = self.tab_widget.indexOf(current_tab)
        closing_widget=self.tab_widget.widget(current_tab)


        # when trying to be closed, widget might re-send a request to be
        # closed again, but will be deleted when event will be processed. So
        # need to check that widget still exists and skip if not. One example
        # of this is when 'exit' is sent in a slave tab. 'exit' will be
        # re-sent by this function on the master widget, which ask all slave
        # widgets to exit
        if closing_widget is None:
            return

        #get a list of all slave widgets on the same kernel.
        slave_tabs = self.find_slave_widgets(closing_widget)

        keepkernel = None #Use the prompt by default
        if hasattr(closing_widget,'_keep_kernel_on_exit'): #set by exit magic
            keepkernel = closing_widget._keep_kernel_on_exit
            # If signal sent by exit magic (_keep_kernel_on_exit, exist and not None)
            # we set local slave tabs._hidden to True to avoid prompting for kernel
            # restart when they get the signal. and then "forward" the 'exit'
            # to the main window
            if keepkernel is not None:
                for tab in slave_tabs:
                    tab._hidden = True
                if closing_widget in slave_tabs:
                    try :
                        self.find_master_tab(closing_widget).execute('exit')
                    except AttributeError:
                        self.log.info("Master already closed or not local, closing only current tab")
                        self.tab_widget.removeTab(current_tab)
                    self.update_tab_bar_visibility()
                    return

        kernel_client = closing_widget.kernel_client
        kernel_manager = closing_widget.kernel_manager

        if keepkernel is None and not closing_widget._confirm_exit:
            # don't prompt, just terminate the kernel if we own it
            # or leave it alone if we don't
            keepkernel = closing_widget._existing
        if keepkernel is None: #show prompt
            if kernel_client and kernel_client.channels_running:
                title = self.window().windowTitle()
                cancel = QtWidgets.QMessageBox.Cancel
                okay = QtWidgets.QMessageBox.Ok
                if closing_widget._may_close:
                    msg = "You are closing the tab : "+'"'+self.tab_widget.tabText(current_tab)+'"'
                    info = "Would you like to quit the Kernel and close all attached Consoles as well?"
                    justthis = QtWidgets.QPushButton("&No, just this Tab", self)
                    justthis.setShortcut('N')
                    closeall = QtWidgets.QPushButton("&Yes, close all", self)
                    closeall.setShortcut('Y')
                    # allow ctrl-d ctrl-d exit, like in terminal
                    closeall.setShortcut('Ctrl+D')
                    box = QtWidgets.QMessageBox(QtWidgets.QMessageBox.Question,
                                            title, msg)
                    box.setInformativeText(info)
                    box.addButton(cancel)
                    box.addButton(justthis, QtWidgets.QMessageBox.NoRole)
                    box.addButton(closeall, QtWidgets.QMessageBox.YesRole)
                    box.setDefaultButton(closeall)
                    box.setEscapeButton(cancel)
                    pixmap = QtGui.QPixmap(self._app.icon.pixmap(QtCore.QSize(64,64)))
                    box.setIconPixmap(pixmap)
                    reply = box.exec_()
                    if reply == 1: # close All
                        for slave in slave_tabs:
                            background(slave.kernel_client.stop_channels)
                            self.tab_widget.removeTab(self.tab_widget.indexOf(slave))
                        kernel_manager.shutdown_kernel()
                        self.tab_widget.removeTab(current_tab)
                        background(kernel_client.stop_channels)
                    elif reply == 0: # close Console
                        if not closing_widget._existing:
                            # Have kernel: don't quit, just close the tab
                            closing_widget.execute("exit True")
                        self.tab_widget.removeTab(current_tab)
                        background(kernel_client.stop_channels)
                else:
                    reply = QtWidgets.QMessageBox.question(self, title,
                        "Are you sure you want to close this Console?"+
                        "\nThe Kernel and other Consoles will remain active.",
                        okay|cancel,
                        defaultButton=okay
                        )
                    if reply == okay:
                        self.tab_widget.removeTab(current_tab)
        elif keepkernel: #close console but leave kernel running (no prompt)
            self.tab_widget.removeTab(current_tab)
            background(kernel_client.stop_channels)
        else: #close console and kernel (no prompt)
            self.tab_widget.removeTab(current_tab)
            if kernel_client and kernel_client.channels_running:
                for slave in slave_tabs:
                    background(slave.kernel_client.stop_channels)
                    self.tab_widget.removeTab(self.tab_widget.indexOf(slave))
                if kernel_manager:
                    kernel_manager.shutdown_kernel()
                background(kernel_client.stop_channels)

        self.update_tab_bar_visibility()
 Called when you need to try to close a tab.

        It takes the number of the tab to be closed as argument, or a reference
        to the widget inside this tab
        
angrmanagement/vendor/qtconsole/mainwindow.py