Simplify data to object conversion

Instead of two methods we now have one that does the appropriate
action based on the input type.

setra_client/client.py

@@ -2,7 +2,7 @@
 import logging
 import urllib.parse
 from datetime import date
-from typing import Union, Optional
+from typing import Union, Optional, List
 
 import requests
 
@@ -187,16 +187,17 @@ class SetraClient(object):
     def post(self, url, **kwargs):
         return self.call('POST', url, **kwargs)
 
-    def object_or_data(self, cls, data) -> Union[object, dict]:
-        if not self.return_objects:
-            return data
-        return cls.from_dict(data)
-
-    def objectlist_or_data(self, cls, data) -> Union[object, dict]:
+    def object_or_data(
+            self, cls, data: Union[dict, List[dict]]
+    ) -> Union[object, dict]:
         """Create list of objects or return data as is"""
         if not self.return_objects:
             return data
-        return [cls.from_dict(i) for i in data]
+        if isinstance(data, dict):
+            return cls.from_dict(data)
+        if isinstance(data, list):
+            return [cls.from_dict(i) for i in data]
+        raise TypeError(f"Expected list or dict, got {type(data)}")
 
     def get_batch(self,
                   batch_id: Optional[int] = None,
@@ -282,7 +283,7 @@ class SetraClient(object):
         if interface:
             queryparams = {"interface": interface}
         response = self.get(url, params=queryparams)
-        return self.objectlist_or_data(Parameter, response.json())
+        return self.object_or_data(Parameter, response.json())
 
 
 def get_client(config_dict):