bpo-42116: Fix inspect.getsource handling of trailing comments (GH-23630)

diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 71c4f27..172e6bf 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -390,6 +390,7 @@ def test_getclasses(self):
                           ('ParrotDroppings', mod.ParrotDroppings),
                           ('StupidGit', mod.StupidGit),
                           ('Tit', mod.MalodorousPervert),
+                          ('WhichComments', mod.WhichComments),
                          ])
         tree = inspect.getclasstree([cls[1] for cls in classes])
         self.assertEqual(tree,
@@ -403,7 +404,8 @@ def test_getclasses(self):
                             [(mod.FesteringGob, (mod.MalodorousPervert,
                                                     mod.ParrotDroppings))
                              ]
-                            ]
+                            ],
+                            (mod.WhichComments, (object,),)
                            ]
                           ])
         tree = inspect.getclasstree([cls[1] for cls in classes], True)
@@ -415,7 +417,8 @@ def test_getclasses(self):
                             [(mod.FesteringGob, (mod.MalodorousPervert,
                                                     mod.ParrotDroppings))
                              ]
-                            ]
+                            ],
+                            (mod.WhichComments, (object,),)
                            ]
                           ])
 
@@ -646,6 +649,18 @@ def test_anonymous(self):
         # as argument to another function.
         self.assertSourceEqual(mod2.anonymous, 55, 55)
 
+class TestBlockComments(GetSourceBase):
+    fodderModule = mod
+
+    def test_toplevel_class(self):
+        self.assertSourceEqual(mod.WhichComments, 96, 114)
+
+    def test_class_method(self):
+        self.assertSourceEqual(mod.WhichComments.f, 99, 104)
+
+    def test_class_async_method(self):
+        self.assertSourceEqual(mod.WhichComments.asyncf, 109, 112)
+
 class TestBuggyCases(GetSourceBase):
     fodderModule = mod2
 
@@ -4014,8 +4029,8 @@ def test_getsource_reload(self):
 
 def test_main():
     run_unittest(
-        TestDecorators, TestRetrievingSourceCode, TestOneliners, TestBuggyCases,
-        TestInterpreterStack, TestClassesAndFunctions, TestPredicates,
+        TestDecorators, TestRetrievingSourceCode, TestOneliners, TestBlockComments,
+        TestBuggyCases, TestInterpreterStack, TestClassesAndFunctions, TestPredicates,
         TestGetcallargsFunctions, TestGetcallargsMethods,
         TestGetcallargsUnboundMethods, TestGetattrStatic, TestGetGeneratorState,
         TestNoEOL, TestSignatureObject, TestSignatureBind, TestParameterObject,