[ModelicaSystem] update handling of xml_file

Author: syntron

OMPython/ModelicaSystem.py

@@ -481,8 +481,10 @@ def buildModel(self, variableFilter: Optional[str] = None):
         buildModelResult = self._requestApi("buildModel", self._model_name, properties=varFilter)
         logger.debug("OM model build result: %s", buildModelResult)
 
-        self._xml_file = pathlib.Path(buildModelResult[0]).parent / buildModelResult[1]
-        self._xmlparse()
+        xml_file = pathlib.Path(buildModelResult[0]).parent / buildModelResult[1]
+        self._xmlparse(xml_file=xml_file)
+        # TODO: remove _xml_file?!
+        self._xml_file = xml_file
 
     def sendExpression(self, expr: str, parsed: bool = True):
         try:
@@ -508,11 +510,11 @@ def _requestApi(self, apiName, entity=None, properties=None):  # 2
 
         return self.sendExpression(exp)
 
-    def _xmlparse(self):
-        if not self._xml_file.is_file():
-            raise ModelicaSystemError(f"XML file not generated: {self._xml_file}")
+    def _xmlparse(self, xml_file: pathlib.Path):
+        if not xml_file.is_file():
+            raise ModelicaSystemError(f"XML file not generated: {xml_file}")
 
-        tree = ET.parse(self._xml_file)
+        tree = ET.parse(xml_file)
         rootCQ = tree.getroot()
         for attr in rootCQ.iter('DefaultExperiment'):
             for key in ("startTime", "stopTime", "stepSize", "tolerance",