The default value of asyncio.StreamReader *limit* is `_DEFAULT_LIMIT` instead of `None`.
<!-- issue-number: [bpo-34613](https://www.bugs.python.org/issue34613) -->
https://bugs.python.org/issue34613
<!-- /issue-number -->
StreamReader
============
-.. class:: StreamReader(limit=None, loop=None)
+.. class:: StreamReader(limit=_DEFAULT_LIMIT, loop=None)
This class is :ref:`not thread safe <asyncio-multithreading>`.
+ The *limit* argument's default value is set to _DEFAULT_LIMIT which is 2**16 (64 KiB)
+
.. method:: exception()
Get the exception.