added changes for xml serialization

Author: mqnifestkelvin

src/modelspec/base_types.py

@@ -122,8 +122,8 @@ def to_xml(self) -> str:
         """
         from modelspec.utils import build_xml_element
 
-        root = ET.Element("modelspec")
-        build_xml_element(root, self.to_dict())
+        # root = ET.Element("modelspec")
+        root = build_xml_element(self)
 
         xml_string = ET.tostring(
             root, encoding="utf-8", xml_declaration=False, method="xml"
@@ -273,12 +273,12 @@ def to_xml_file(
         if filename is None:
             filename = f"{self.id}.xml"
 
-        root = ET.Element(root_name)
+        # root = ET.Element(root_name)
 
-        build_xml_element(root, self.to_dict())
+        root = build_xml_element(self)
 
         # Create an ElementTree object with the root element
-        tree = ET.ElementTree(root)
+        # tree = ET.ElementTree(root)
 
         # Generate the XML string
         xml_str = ET.tostring(root, encoding="utf-8", method="xml").decode("utf-8")