Closes #19434: fix copy-paste error in MIMENonMultipart docstring.
diff --git a/Lib/email/mime/nonmultipart.py b/Lib/email/mime/nonmultipart.py
index fc3b9eb..e1f5196 100644
--- a/Lib/email/mime/nonmultipart.py
+++ b/Lib/email/mime/nonmultipart.py
@@ -12,7 +12,7 @@
 
 
 class MIMENonMultipart(MIMEBase):
-    """Base class for MIME multipart/* type messages."""
+    """Base class for MIME non-multipart type messages."""
 
     def attach(self, payload):
         # The public API prohibits attaching multiple subparts to MIMEBase