fix bugbear caching of class instance

weldx_widgets/widget_base.py

@@ -131,15 +131,19 @@ def schema(self) -> str:
         """Return a schema name is used to validate input and output."""
         pass
 
+    @staticmethod
     @functools.lru_cache
-    def get_schema_path(self) -> Path:
+    def _get_schema_path(schema) -> Path:
         """Resolve a schema name to path."""
-        return get_schema_path(self.schema)
+        return get_schema_path(schema)
+
+    def get_schema_path(self) -> Path:
+        return WeldxImportExport._get_schema_path(self.schema)
 
     def validate(self, tree):
         """Validate given tree against schema of this class."""
         # should be implemented such that we can validate both input and output.
-        pass
+        return
 
     @abc.abstractmethod
     def from_tree(self, tree: dict):

weldx_widgets/widget_gmaw.py

@@ -306,16 +306,17 @@ def __init__(self, process_type="spray"):
     def _create_process_widgets(self, change):
         new = change["new"]
         arg = self.translate[new]
-        box = self._cached_process_widgets(arg)
+        box = WidgetGMAW._cached_process_widgets(arg)
         self._welding_process.children = (box,)
 
     @property
     def welding_process(self) -> Union[ProcessSpray, ProcessPulsed]:
         """Return welding process widget."""
         return self._welding_process.children[0]
 
+    @staticmethod
     @lru_cache(None)
-    def _cached_process_widgets(self, process):
+    def _cached_process_widgets(process):
         if process == "spray":
             return ProcessSpray()