gnome-shell/data/dbus-interfaces/org.freedesktop.login1.Manager.xml

<node>
  <interface name="org.freedesktop.login1.Manager">
    <method name="Suspend">
      <arg type="b" direction="in"/>
    </method>
    <method name="CanSuspend">
      <arg type="s" direction="out"/>
    </method>
    <method name="Inhibit">
      <arg type="s" direction="in"/>
      <arg type="s" direction="in"/>
      <arg type="s" direction="in"/>
      <arg type="s" direction="in"/>
      <arg type="h" direction="out"/>
    </method>
    <method name="GetSession">
      <arg type="s" direction="in"/>
      <arg type="o" direction="out"/>
    </method>
    <method name="ListSessions">
      <arg name="sessions" type="a(susso)" direction="out"/>
    </method>
    <method name="CanRebootToBootLoaderMenu">
      <arg type="s" direction="out"/>
    </method>
    <method name="SetRebootToBootLoaderMenu">
      <arg type="t" direction="in"/>
    </method>
    <signal name="PrepareForSleep">
      <arg type="b" direction="out"/>
    </signal>
  </interface>
</node>