From c1f00ce5d30b37ca37675d2b1084522363f8143a Mon Sep 17 00:00:00 2001
From: Matthias Bernt <m.bernt@ufz.de>
Date: Tue, 11 Jan 2022 23:13:32 +0100
Subject: [PATCH] add docstring

---
 lib/galaxy/util/xml_macros.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/galaxy/util/xml_macros.py b/lib/galaxy/util/xml_macros.py
index b08e0fc92a84..401793cc3b20 100644
--- a/lib/galaxy/util/xml_macros.py
+++ b/lib/galaxy/util/xml_macros.py
@@ -157,6 +157,9 @@ def _expand_macro(element, expand_el, macros, tokens):
 
 def _expand_yield_statements(macro_def, expand_el):
     """
+    Modifies the macro_def element by replacing all <yield/> tags below the
+    macro_def element by the children  of the expand_el
+    
     >>> from lxml.etree import tostring
     >>> from galaxy.util import XML
     >>> expand_el = XML('''