How to use the xonsh.events.events function in xonsh

from xonsh.execer import Execer
from xonsh.proc import HiddenCommandPipeline
from xonsh.jobs import ignore_sigtstp
from xonsh.tools import setup_win_unicode_console, print_color, to_bool_or_int
from xonsh.platform import HAS_PYGMENTS, ON_WINDOWS
from xonsh.codecache import run_script_with_cache, run_code_with_cache
from xonsh.xonfig import print_welcome_screen
from xonsh.xontribs import xontribs_load
from xonsh.lazyimps import pygments, pyghooks
from xonsh.imphooks import install_import_hooks
from xonsh.events import events
from xonsh.environ import xonshrc_context, make_args_env
from xonsh.built_ins import XonshSession, load_builtins


events.transmogrify("on_post_init", "LoadEvent")
events.doc(
    "on_post_init",
    """
on_post_init() -> None

Fired after all initialization is finished and we're ready to do work.

NOTE: This is fired before the wizard is automatically started.
""",
)

events.transmogrify("on_exit", "LoadEvent")
events.doc(
    "on_exit",
    """
on_exit() -> None

execer = Execer(
        xonsh_ctx=ctx,
        debug_level=debug,
        scriptcache=shell_kwargs.get("scriptcache", True),
        cacheall=shell_kwargs.get("cacheall", False),
    )
    events.on_timingprobe.fire(name="post_execer_init")
    # load rc files
    login = shell_kwargs.get("login", True)
    env = builtins.__xonsh__.env
    rc = shell_kwargs.get("rc", None)
    rc = env.get("XONSHRC") if rc is None else rc
    if args.mode != XonshMode.interactive and not args.force_interactive:
        #  Don't load xonshrc if not interactive shell
        rc = None
    events.on_pre_rc.fire()
    xonshrc_context(rcfiles=rc, execer=execer, ctx=ctx, env=env, login=login)
    events.on_post_rc.fire()
    # create shell
    builtins.__xonsh__.shell = Shell(execer=execer, **shell_kwargs)
    ctx["__name__"] = "__main__"
    return env

def default(self, line):
        """Implements code execution."""
        line = line if line.endswith("\n") else line + "\n"
        src, code = self.push(line)
        if code is None:
            return

        events.on_precommand.fire(cmd=src)

        env = builtins.__xonsh_env__
        hist = builtins.__xonsh_history__  # pylint: disable=no-member
        ts1 = None
        enc = env.get("XONSH_ENCODING")
        err = env.get("XONSH_ENCODING_ERRORS")
        tee = Tee(encoding=enc, errors=err)
        try:
            ts0 = time.time()
            run_compiled_code(code, self.ctx, None, "single")
            ts1 = time.time()
            if hist is not None and hist.last_cmd_rtn is None:
                hist.last_cmd_rtn = 0  # returncode for success
        except XonshError as e:
            print(e.args[0], file=sys.stderr)
            if hist is not None and hist.last_cmd_rtn is None:

debug_level=debug,
        scriptcache=shell_kwargs.get("scriptcache", True),
        cacheall=shell_kwargs.get("cacheall", False),
    )
    events.on_timingprobe.fire(name="post_execer_init")
    # load rc files
    login = shell_kwargs.get("login", True)
    env = builtins.__xonsh__.env
    rc = shell_kwargs.get("rc", None)
    rc = env.get("XONSHRC") if rc is None else rc
    if args.mode != XonshMode.interactive and not args.force_interactive:
        #  Don't load xonshrc if not interactive shell
        rc = None
    events.on_pre_rc.fire()
    xonshrc_context(rcfiles=rc, execer=execer, ctx=ctx, env=env, login=login)
    events.on_post_rc.fire()
    # create shell
    builtins.__xonsh__.shell = Shell(execer=execer, **shell_kwargs)
    ctx["__name__"] = "__main__"
    return env

def exec_module(self, module):
        """Executes the module in its own namespace."""
        events.on_import_pre_exec_module.fire(module=module)
        rtn = self.loader.exec_module(module)
        events.on_import_post_exec_module.fire(module=module)
        return rtn

pass
            else:
                # OK PWD is really gone.
                msg = "{UNDERLINE_INTENSE_WHITE}{BACKGROUND_INTENSE_BLACK}"
                msg += "xonsh: working directory does not exist: " + pwd
                msg += "{NO_COLOR}"
                self.print_color(msg, file=sys.stderr)
        elif "PWD" not in env:
            # $PWD is missing from env, recreate it
            env["PWD"] = cwd
        elif os.path.realpath(cwd) != os.path.realpath(env["PWD"]):
            # The working directory has changed without updating $PWD, fix this
            old = env["PWD"]
            env["PWD"] = cwd
            env["OLDPWD"] = old
            events.on_chdir.fire(olddir=old, newdir=cwd)

def _post_run_event_fire(self, name, proc):
        event_name = "on_post_spec_run_" + name
        if events.exists(event_name):
            event = getattr(events, event_name)
            event.fire(spec=self, proc=proc)

NOTE: All the caveats of the ``atexit`` module also apply to this event.
""",
)

events.transmogrify("on_pre_rc", "LoadEvent")
events.doc(
    "on_pre_rc",
    """
on_pre_rc() -> None

Fired just before rc files are loaded, if they are.
""",
)

events.transmogrify("on_post_rc", "LoadEvent")
events.doc(
    "on_post_rc",
    """
on_post_rc() -> None

Fired just after rc files are loaded, if they are.
""",
)


def get_setproctitle():
    """Proxy function for loading process title"""
    try:
        from setproctitle import setproctitle as spt
    except ImportError:
        return

}
        if builtins.__xonsh__.env.get("COLOR_INPUT"):
            style = style_from_pygments_dict(DEFAULT_STYLE_DICT)

            prompt_args["style"] = style

            style_overrides_env = env.get("PTK_STYLE_OVERRIDES")
            if style_overrides_env:
                try:
                    style_overrides = Style.from_dict(style_overrides_env)
                    prompt_args["style"] = merge_styles([style, style_overrides])
                except (AttributeError, TypeError, ValueError):
                    print_exception()

        line = self.prompter.prompt(**prompt_args)
        events.on_post_prompt.fire()
        return line

""",
)

events.transmogrify("on_post_cmdloop", "LoadEvent")
events.doc(
    "on_post_cmdloop",
    """
on_post_cmdloop() -> None

Fired just after the command loop finishes, if it is.

NOTE: All the caveats of the ``atexit`` module also apply to this event.
""",
)

events.transmogrify("on_pre_rc", "LoadEvent")
events.doc(
    "on_pre_rc",
    """
on_pre_rc() -> None

Fired just before rc files are loaded, if they are.
""",
)

events.transmogrify("on_post_rc", "LoadEvent")
events.doc(
    "on_post_rc",
    """
on_post_rc() -> None

Fired just after rc files are loaded, if they are.