Switch to plugin.

def switch_to_plugin(self):
        """Switch to plugin."""
        # Unmaxizime currently maximized plugin
        if (self.main.last_plugin is not None and
                self.main.last_plugin.ismaximized and
                self.main.last_plugin is not self):
            self.main.maximize_dockwidget()

        # Show plugin only if it was already visible
        if self.get_option('visible_if_project_open'):
            if not self.toggle_view_action.isChecked():
                self.toggle_view_action.setChecked(True)
            self.visibility_changed(True)