diff --git a/README.md b/README.md
index f03a289b..a9687950 100644
--- a/README.md
+++ b/README.md
@@ -92,6 +92,19 @@ python3 -m cProfile -o profiler.bin tests/test.ui.004.py
 cprofilev -f profiler.bin
 # open http://127.0.0.1:4000
 ```
+##### py-spy
+```bash
+# install
+pip install py-spy
+
+# run the application
+python3 demo/demo.py
+
+# on another terminal run the py-spy
+sudo env "PATH=$PATH" \
+    py-spy top \
+       --pid  $(ps -A -o pid,cmd | grep demo.py | grep -v grep | sed 's,python.*,,')
+```
 ##### pyroscope
 [pyroscope](https://pyroscope.io/) can be used as well for profiling
 
diff --git a/tests/test.generic.006.weakref.01.py b/tests/test.generic.006.weakref.01.py
new file mode 100644
index 00000000..e1e32126
--- /dev/null
+++ b/tests/test.generic.006.weakref.01.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+
+# MIT License
+#
+# Copyright (c) 2023 Eugenio Parodi <ceccopierangiolieugenio AT googlemail DOT com>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+import weakref
+import gc
+
+class C:
+    def method(self):
+        print("method called!")
+        return 1234
+
+c = C()
+r = weakref.ref(c.method)
+
+print(f"{r=}")
+print(f"{r()=}")
+
+r = weakref.WeakMethod(c.method)
+
+print(f"{r=}")
+print(f"{r()=}")
+print(f"{r()()=}")
+
+del c
+
+print(f"{gc.collect()=}")
+
+print(f"{r()=}")
+
+def m3():
+    print("Method 3")
+m = m3
+l = lambda : print("lambda1")
+r3 = weakref.WeakMethod(m3)
+
+r2 = weakref.WeakMethod(lambda : print("Method 2"))
+
+r2()
+r3()
diff --git a/tests/test.generic.006.weakref.02.py b/tests/test.generic.006.weakref.02.py
new file mode 100644
index 00000000..acc1aebe
--- /dev/null
+++ b/tests/test.generic.006.weakref.02.py
@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+
+# MIT License
+#
+# Copyright (c) 2023 Eugenio Parodi <ceccopierangiolieugenio AT googlemail DOT com>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+import weakref
+class Object:
+    pass
+
+kenny = Object()
+weakref.finalize(kenny, print, "You killed Kenny!")
+
+del kenny
\ No newline at end of file