'Called at the beginning of a request before  `get`/`post`/etc.
Override this method to perform common initialization regardless
of the request method.
Asynchronous support: Decorate this method with `.gen.coroutine`
or `.return_future` to make it asynchronous (the
`asynchronous` decorator cannot be used on `prepare`).
If this method returns a `.Future` execution will not proceed
until the `.Future` is done.
.. versionadded:: 3.1
Asynchronous support.'

def prepare(self):

    pass
