Add changes from PR

Author: MrTeale

CHANGELOG.md

@@ -10,8 +10,9 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 [#2003](https://github.com/plotly/dash/issues/2003) in which 
 `dangerously_allow_html=True` + `mathjax=True` works in some cases, and in some cases not.
 
-- [#2049](https://github.com/plotly/dash/pull/2043) Added `wait_for_class_to_equal` and `wait_for_contains_class` methods to `dash.testing`
+### Added
 
+- [#2049](https://github.com/plotly/dash/pull/2043) Added `wait_for_class_to_equal` and `wait_for_contains_class` methods to `dash.testing`
 
 ## [2.4.1] - 2022-05-11
 

dash/testing/wait.py

@@ -80,7 +80,7 @@ def __call__(self, driver):
             logger.debug(
                 "contains class {%s} => expected %s", classname, self.classname
             )
-            return self.classname in str(classname)
+            return self.classname in str(classname).split(" ")
         except WebDriverException:
             return False