diff --git a/tableau_rest_api/methods/datasource.py b/tableau_rest_api/methods/datasource.py
index 2b25f35..db97857 100644
--- a/tableau_rest_api/methods/datasource.py
+++ b/tableau_rest_api/methods/datasource.py
@@ -125,7 +125,7 @@ def update_datasource_connection_by_luid(self, datasource_luid: str, new_server_
                                              new_connection_username: Optional[str] = None,
                                              new_connection_password: Optional[str] = None) -> ET.Element:
         self.start_log_block()
-        tsr = self.__build_connection_update_xml(new_server_address, new_server_port,
+        tsr = self.rest_api_base.__build_connection_update_xml(new_server_address, new_server_port,
                                                             new_connection_username,
                                                             new_connection_password)
         url = self.build_api_url("datasources/{}/connection".format(datasource_luid))
diff --git a/tableau_rest_api/methods/rest_api_base.py b/tableau_rest_api/methods/rest_api_base.py
index 72e3355..5c78934 100644
--- a/tableau_rest_api/methods/rest_api_base.py
+++ b/tableau_rest_api/methods/rest_api_base.py
@@ -187,13 +187,12 @@ def build_api_url(self, call: str, server_level: bool = False,
     def build_url_parameter_string(map_dict: Optional[Dict] = None, name_value_tuple_list: Optional[List[Tuple]] = None,
                                    hand_built_portion: Optional[str] = None):
         encoded_list = None
-        if len(name_value_tuple_list) == 0:
-            encoded_list = None
-        else:
-            for v in name_value_tuple_list:
-                if len(v) != 2:
-                    raise InvalidOptionException('Each element should have a two-element Tuples (Name, Value)')
-                encoded_list = urlencode(name_value_tuple_list)
+        if name_value_tuple_list is not None:
+            if len(name_value_tuple_list) > 0:
+                for v in name_value_tuple_list:
+                    if len(v) != 2:
+                        raise InvalidOptionException('Each element should have a two-element Tuples (Name, Value)')
+                    encoded_list = urlencode(name_value_tuple_list)
 
         if hand_built_portion is not None and encoded_list is None:
             final_string = hand_built_portion
diff --git a/tableau_rest_api/methods/workbook.py b/tableau_rest_api/methods/workbook.py
index 2bd87bd..db80e3e 100644
--- a/tableau_rest_api/methods/workbook.py
+++ b/tableau_rest_api/methods/workbook.py
@@ -166,7 +166,7 @@ def update_workbook_connection_by_luid(self, wb_luid: str, connection_luid: str,
                                            new_connection_username: Optional[str] = None,
                                            new_connection_password: Optional[str] = None) -> ET.Element:
         self.start_log_block()
-        tsr = self.__build_connection_update_xml(new_server_address, new_server_port, new_connection_username,
+        tsr = self.rest_api_base.__build_connection_update_xml(new_server_address, new_server_port, new_connection_username,
                                                  new_connection_password)
         url = self.build_api_url("workbooks/{}/connections/{}".format(wb_luid, connection_luid))
         response = self.send_update_request(url, tsr)