Type fix for _get_converter

Author: caufieldjh

src/linkml_reference_validator/plugins/reference_validation_plugin.py

@@ -303,17 +303,16 @@ def _get_converter(self) -> Optional[Converter]:
                 return None
             schema = self.schema_view.schema
             if schema and schema.prefixes:
-                # schema.prefixes is a dict of prefix name -> Prefix object
-                # The Prefix object has a prefix_reference attribute with the URI
-                prefix_map = {
-                    name: (
-                        prefix.get("prefix_reference")
-                        if isinstance(prefix, dict) and "prefix_reference" in prefix
-                        else str(prefix)
-                    )
-                    for name, prefix in schema.prefixes.items()
-                }
-                return Converter.from_prefix_map(prefix_map)
+                # schema.prefixes is a list of Prefix objects
+                # Each Prefix object has a prefix_name and prefix_reference attribute
+                prefix_map: dict[str, str] = {}
+                for prefix in schema.prefixes:
+                    prefix_name = getattr(prefix, "prefix_name", None)
+                    prefix_reference = getattr(prefix, "prefix_reference", None)
+                    if isinstance(prefix_name, str) and prefix_reference is not None:
+                        prefix_map[prefix_name] = str(prefix_reference)
+                if prefix_map:
+                    return Converter.from_prefix_map(prefix_map)
             return None
 
         # type: ignore