fixing fio runner
diff --git a/wally/node_interfaces.py b/wally/node_interfaces.py
index 8552a3d..c494b8d 100644
--- a/wally/node_interfaces.py
+++ b/wally/node_interfaces.py
@@ -66,6 +66,10 @@
     rpc_log_file = None  # type: str
 
     @abc.abstractmethod
+    def __str__(self) -> str:
+        pass
+
+    @abc.abstractmethod
     def run(self, cmd: str, timeout: int = 60, nolog: bool = False) -> str:
         pass
 
@@ -82,10 +86,6 @@
         pass
 
     @abc.abstractmethod
-    def get_interface(self, ip: str) -> str:
-        pass
-
-    @abc.abstractmethod
     def stat_file(self, path:str) -> Any:
         pass