View application behavior in the current window.

def view_current_app_behavior(self) -> str:
        '''View application behavior in the current window.'''
        output, _ = self._execute(
            '-s', self.device_sn, 'shell', 'dumpsys', 'window', 'windows')
        return re.findall(r'mCurrentFocus=.+(com[a-zA-Z0-9\.]+/.[a-zA-Z0-9\.]+)', output)[0]