Add ObservableCollection.is_empty() and IntValue.equals()

Author: FancyNeuron

src/spellbind/observable_sequences.py

@@ -752,7 +752,7 @@ def _to_value(value: _S | Value[_S],
     if checker(value):
         return constant_factory(value)
     else:
-        return value
+        return value  # type: ignore[return-value]  # mypy raises an error since mypy 1.18.1, but that seems to be a bug https://github.com/python/mypy/issues/20330
 
 
 def _to_values(values: Iterable[_S | Value[_S]],

tests/test_collections/test_observable_lists/test_observable_list_is_empty.py

@@ -1,5 +1,5 @@
 from conftest import OneParameterObserver
-from spellbind.observable_sequences import ObservableList, SimpleValueChangedMultipleTimesAction
+from spellbind.observable_sequences import ObservableList
 
 
 def test_empty_is_empty():