class WebDAVHandler(RequestHandler):
     SUPPORTED_METHODS = RequestHandler.SUPPORTED_METHODS + ('PROPFIND',)

     def propfind(self):
         pass

   def prepare(self):
       if self.request.headers['Content-Type'] == 'application/x-json':
           self.args = json_decode(self.request.body)
       # Access self.args directly instead of using self.get_argument.

  The `tornado.httputil.HTTPServerRequest` object containing additional
  request parameters including e.g. headers and body data.

  The ``path_args`` and ``path_kwargs`` attributes contain the
  positional and keyword arguments that are passed to the
  :ref:`HTTP verb methods <verbs>`.  These attributes are set
  before those methods are called, so the values are available
  during `prepare`.

  Deprecated alias for ``get_signed_cookie``.

  .. deprecated:: 6.3

  Deprecated alias for ``get_signed_cookie_key_version``.

  .. deprecated:: 6.3

  Deprecated alias for ``set_signed_cookie``.

  .. deprecated:: 6.3

  The `Application` object serving this request

  .. attribute:: settings

     Additional keyword arguments passed to the constructor are
     saved in the `settings` dictionary, and are often referred to
     in documentation as "application settings".  Settings are
     used to customize various aspects of Tornado (although in
     some cases richer customization is possible by overriding
     methods in a subclass of `RequestHandler`).  Some
     applications also like to use the `settings` dictionary as a
     way to make application-specific settings available to
     handlers without using global variables.  Settings used in
     Tornado are described below.

     General settings:

     * ``autoreload``: If ``True``, the server process will restart
       when any source files change, as described in :ref:`debug-mode`.
       This option is new in Tornado 3.2; previously this functionality
       was controlled by the ``debug`` setting.
     * ``debug``: Shorthand for several debug mode settings,
       described in :ref:`debug-mode`.  Setting ``debug=True`` is
       equivalent to ``autoreload=True``, ``compiled_template_cache=False``,
       ``static_hash_cache=False``, ``serve_traceback=True``.
     * ``default_handler_class`` and ``default_handler_args``:
       This handler will be used if no other match is found;
       use this to implement custom 404 pages (new in Tornado 3.2).
     * ``compress_response``: If ``True``, responses in textual formats
       will be compressed automatically.  New in Tornado 4.0.
     * ``gzip``: Deprecated alias for ``compress_response`` since
       Tornado 4.0.
     * ``log_function``: This function will be called at the end
       of every request to log the result (with one argument, the
       `RequestHandler` object).  The default implementation
       writes to the `logging` module's root logger.  May also be
       customized by overriding `Application.log_request`.
     * ``serve_traceback``: If ``True``, the default error page
       will include the traceback of the error.  This option is new in
       Tornado 3.2; previously this functionality was controlled by
       the ``debug`` setting.
     * ``ui_modules`` and ``ui_methods``: May be set to a mapping
       of `UIModule` or UI methods to be made available to templates.
       May be set to a module, dictionary, or a list of modules
       and/or dicts.  See :ref:`ui-modules` for more details.
     * ``websocket_ping_interval``: If the ping interval has a non-zero
       value, a ping will be sent periodically every
       ``websocket_ping_interval`` seconds, and the connection will be
       closed if a response is not received before the
       ``websocket_ping_timeout``.
       This can help keep the connection alive through certain proxy
       servers which close idle connections, and it can detect if the
       websocket has failed without being properly closed.
     * ``websocket_ping_timeout``: For use with ``websocket_ping_interval``,
       if the server does not receive a pong within this many seconds, it
       will close the websocket_ping_timeout.
       The default timeout is equal to the ping interval. The ping timeout
       will be turned off if the ping interval is not set or if the
       timeout is set to ``0``.
       This can help to detect disconnected clients to avoid keeping
       inactive connections open.

     Authentication and security settings:

     * ``cookie_secret``: Used by `RequestHandler.get_signed_cookie`
       and `.set_signed_cookie` to sign cookies.
     * ``key_version``: Used by requestHandler `.set_signed_cookie`
       to sign cookies with a specific key when ``cookie_secret``
       is a key dictionary.
     * ``login_url``: The `authenticated` decorator will redirect
       to this url if the user is not logged in.  Can be further
       customized by overriding `RequestHandler.get_login_url`
     * ``xsrf_cookies``: If ``True``, :ref:`xsrf` will be enabled.
     * ``xsrf_cookie_version``: Controls the version of new XSRF
       cookies produced by this server.  Should generally be left
       at the default (which will always be the highest supported
       version), but may be set to a lower value temporarily
       during version transitions.  New in Tornado 3.2.2, which
       introduced XSRF cookie version 2.
     * ``xsrf_cookie_kwargs``: May be set to a dictionary of
       additional arguments to be passed to `.RequestHandler.set_cookie`
       for the XSRF cookie.
     * ``xsrf_cookie_name``: Controls the name used for the XSRF
       cookie (default ``_xsrf``). The intended use is to take
       advantage of `cookie prefixes`_. Note that cookie prefixes
       interact with other cookie flags, so they must be combined
       with ``xsrf_cookie_kwargs``, such as
       ``{"xsrf_cookie_name": "__Host-xsrf", "xsrf_cookie_kwargs":
       {"secure": True}}``
     * ``twitter_consumer_key``, ``twitter_consumer_secret``,
       ``friendfeed_consumer_key``, ``friendfeed_consumer_secret``,
       ``google_consumer_key``, ``google_consumer_secret``,
       ``facebook_api_key``, ``facebook_secret``:  Used in the
       `tornado.auth` module to authenticate to various APIs.

     .. _cookie prefixes: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie#cookie_prefixes

     Template settings:

     * ``autoescape``: Controls automatic escaping for templates.
       May be set to ``None`` to disable escaping, or to the *name*
       of a function that all output should be passed through.
       Defaults to ``"xhtml_escape"``.  Can be changed on a per-template
       basis with the ``{% autoescape %}`` directive.
     * ``compiled_template_cache``: Default is ``True``; if ``False``
       templates will be recompiled on every request.  This option
       is new in Tornado 3.2; previously this functionality was controlled
       by the ``debug`` setting.
     * ``template_path``: Directory containing template files.  Can be
       further customized by overriding `RequestHandler.get_template_path`
     * ``template_loader``: Assign to an instance of
       `tornado.template.BaseLoader` to customize template loading.
       If this setting is used the ``template_path`` and ``autoescape``
       settings are ignored.  Can be further customized by overriding
       `RequestHandler.create_template_loader`.
     * ``template_whitespace``: Controls handling of whitespace in
       templates; see `tornado.template.filter_whitespace` for allowed
       values. New in Tornado 4.3.

     Static file settings:

     * ``static_hash_cache``: Default is ``True``; if ``False``
       static urls will be recomputed on every request.  This option
       is new in Tornado 3.2; previously this functionality was controlled
       by the ``debug`` setting.
     * ``static_path``: Directory from which static files will be
       served.
     * ``static_url_prefix``:  Url prefix for static files,
       defaults to ``"/static/"``.
     * ``static_handler_class``, ``static_handler_args``: May be set to
       use a different handler for static files instead of the default
       `tornado.web.StaticFileHandler`.  ``static_handler_args``, if set,
       should be a dictionary of keyword arguments to be passed to the
       handler's ``initialize`` method.

  The ``URLSpec`` class is also available under the name ``tornado.web.url``.