Execute a process using subprocess.Popen, setting the backend's DISPLAY

def create_process(self, command, shell=True, stdout=None, stderr=None,
                       env=None):
        """
        Execute a process using subprocess.Popen, setting the backend's DISPLAY
        """
        env = env if env is not None else dict(os.environ)
        env['DISPLAY'] = self.display
        return subprocess.Popen(command, shell=shell,
                                stdout=stdout, stderr=stderr,
                                env=env)