如何向pygobject虚拟终端发送命令？

pip install PyGObject

from gi.repository import GLib, GObject, Gtk
from gi.repository import Vte

terminal = Vte.Terminal()

terminal.connect('child-exited', Gtk.main_quit)

window = Gtk.Window()
window.add(terminal)
window.show_all()

terminal.spawn_async(
    Vte.PtyFlags.DEFAULT,
    None,
    ['/bin/bash'],
    None,
    GLib.SpawnFlags.DO_NOT_REAP_CHILD,
    None,
    None,
    None
)

def send_command(command):
    terminal.feed_child(command + '\n', len(command) + 1)

Gtk.main()

send_command('ls')