code: def register_X_browsers():
      # use xdg-open if around
      if shutil.which("xdg-open"):
          register("xdg-open", None, BackgroundBrowser("xdg-open"))
  
      # Opens an appropriate browser for the URL scheme according to
      # freedesktop.org settings (GNOME, KDE, XFCE, etc.)
      if shutil.which("gio"):
          register(
              "gio",
              None,
              BackgroundBrowser(["gio", "open", "--", "%s"]),
          )
  
      # Equivalent of gio open before 2015
      if "GNOME_DESKTOP_SESSION_ID" in os.environ and shutil.which(
          "gvfs-open"
      ):
          register("gvfs-open", None, BackgroundBrowser("gvfs-open"))
  
      # The default KDE browser
      if "KDE_FULL_SESSION" in os.environ and shutil.which("kfmclient"):
          register("kfmclient", Konqueror, Konqueror("kfmclient"))
  
      if shutil.which("x-www-browser"):
          register(
              "x-www-browser", None, BackgroundBrowser("x-www-browser")
          )
  
      # The Mozilla browsers
      for browser in ("firefox", "iceweasel", "iceape", "seamonkey"):
          if shutil.which(browser):
              register(browser, None, Mozilla(browser))
  
      # The Netscape and old Mozilla browsers
      for browser in (
          "mozilla-firefox",
          "mozilla-firebird",
          "firebird",
          "mozilla",
          "netscape",
      ):
          if shutil.which(browser):
              register(browser, None, Netscape(browser))
  
      # Konqueror/kfm, the KDE browser.
      if shutil.which("kfm"):
          register("kfm", Konqueror, Konqueror("kfm"))
      elif shutil.which("konqueror"):
          register("konqueror", Konqueror, Konqueror("konqueror"))
  
      # Gnome's Galeon and Epiphany
      for browser in ("galeon", "epiphany"):
          if shutil.which(browser):
              register(browser, None, Galeon(browser))
  
      # Skipstone, another Gtk/Mozilla based browser
      if shutil.which("skipstone"):
          register("skipstone", None, BackgroundBrowser("skipstone"))
  
      # Google Chrome/Chromium browsers
      for browser in (
          "google-chrome",
          "chrome",
          "chromium",
          "chromium-browser",
      ):
          if shutil.which(browser):
              register(browser, None, Chrome(browser))
  
      # Opera, quite popular
      if shutil.which("opera"):
          register("opera", None, Opera("opera"))
  
      # Next, Mosaic -- old but still in use.
      if shutil.which("mosaic"):
          register("mosaic", None, BackgroundBrowser("mosaic"))
  
      # Grail, the Python browser. Does anybody still use it?
      if shutil.which("grail"):
          register("grail", Grail, None)
  
imports: import os
  import shlex
  import shutil
  import sys
  import subprocess
  import threading
  import warnings
label_desc: Use image node_id 7 for calling a global function with example usage: register_X_browsers() without return types