Remove dead code identified by Skylos

luigi/db_task_history.py

@@ -59,8 +59,6 @@ class DbTaskHistory(task_history.TaskHistory):
     Also has methods for useful db queries.
     """
 
-    CURRENT_SOURCE_VERSION = 1
-
     @contextmanager
     def _session(self, session=None):
         if session:

luigi/format.py

@@ -180,10 +180,6 @@ def write(self, *args, **kwargs):
             self._process.stdin.flush()
             self._flushcount = 0
 
-    def writeLine(self, line):
-        assert "\n" not in line
-        self.write(line + "\n")
-
     def _finish(self):
         """
         Closes and waits for subprocess to exit.

luigi/process.py

@@ -67,13 +67,6 @@ def get_spool_handler(filename):
     return handler
 
 
-def _server_already_running(pidfile):
-    existing_pid = check_pid(pidfile)
-    if pidfile and existing_pid:
-        return True
-    return False
-
-
 def daemonize(cmd, pidfile=None, logdir=None, api_port=8082, address=None, unix_socket=None):
     import daemon
 

luigi/scheduler.py

@@ -89,7 +89,7 @@ def rpc_method(**request_args):
     def _rpc_method(fn):
         # If request args are passed, return this function again for use as
         # the decorator function with the request args attached.
-        args, varargs, varkw, defaults, kwonlyargs, kwonlydefaults, ann = inspect.getfullargspec(fn)
+        args, varargs, _, defaults, _, _, _ = inspect.getfullargspec(fn)
         assert not varargs
         first_arg, *all_args = args
         assert first_arg == "self"