Add note about frequently-seen pull request to add **kwargs to json_encode.

diff --git a/tornado/escape.py b/tornado/escape.py
index 016fdade82bea68daf393d97b262b703136eaa01..546bd2ea863fa8f47ecc6ac87a0cf68fd46299fb 100644 (file)
--- a/tornado/escape.py
+++ b/tornado/escape.py
@@ -64,6 +64,9 @@ def xhtml_unescape(value):
     return re.sub(r"&(#?)(\w+?);", _convert_entity, _unicode(value))
 
 
+# The fact that json_encode wraps json.dumps is an implementation detail.
+# Please see https://github.com/facebook/tornado/pull/706
+# before sending a pull request that adds **kwargs to this function.
 def json_encode(value):
     """JSON-encodes the given Python object."""
     # JSON permits but does not require forward slashes to be escaped.