Issue #15402: Add a __sizeof__ method to struct.Struct.

Initial patch by Serhiy Storchaka.
diff --git a/Misc/NEWS b/Misc/NEWS
index ff7be30..539c905 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -98,6 +98,10 @@
 Library
 -------
 
+- Issue #15402: An issue in the struct module that caused sys.getsizeof to
+  return incorrect results for struct.Struct instances has been fixed.
+  Initial patch by Serhiy Storchaka.
+
 - Issue #15232: when mangle_from is True, email.Generator now correctly mangles
   lines that start with 'From' that occur in a MIME preamble or epilogue.