'Deprecated alias for `IOLoop.current()`.
.. versionchanged:: 5.0
Previously, this method returned a global singleton
`IOLoop`, in contrast with the per-thread `IOLoop` returned
by `current()`. In nearly all cases the two were the same
(when they differed, it was generally used from non-Tornado
threads to communicate back to the main thread\'s `IOLoop`).
This distinction is not present in `asyncio`, so in order
to facilitate integration with that package `instance()`
was changed to be an alias to `current()`. Applications
using the cross-thread communications aspect of
`instance()` should instead set their own global variable
to point to the `IOLoop` they want to use.
.. deprecated:: 5.0'

@staticmethod
def instance():

    return IOLoop.current()
