[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

ipykernel/displayhook.py

@@ -77,7 +77,6 @@ def reset_thread_parent(self, token):
         """Reset the parent header to undo the set_thread_parent call that returned the token."""
         self._parent_header.reset(token)
 
-
     def set_parent(self, parent):
         """Set the global and thread parent header."""
         self.parent_header = extract_header(parent)
@@ -141,7 +140,6 @@ def parent_header(self, value):
         self._parent_header.set(value)
         self._parent_header_global = value
 
-
     def set_thread_parent(self, parent):
         """Set the parent header for the calling thread only. Returns a reset token that can be used with reset_thread_parent."""
         return self._parent_header.set(extract_header(parent))