Fix some PR comments, cleanup imports

cura/NetworkClient.py

@@ -15,10 +15,10 @@ from cura.CuraApplication import CuraApplication
 #   This was originally part of NetworkedPrinterOutputDevice but was moved out for re-use in other classes.
 class NetworkClient:
     
-    def __init__(self, application: CuraApplication = None):
+    def __init__(self) -> None:
         
         # Use the given application instance or get the singleton instance.
-        self._application = application or CuraApplication.getInstance()
+        self._application = CuraApplication.getInstance()
         
         # Network manager instance to use for this client.
         self._manager = None  # type: Optional[QNetworkAccessManager]
@@ -89,7 +89,7 @@ class NetworkClient:
     def _validateManager(self) -> None:
         if self._manager is None:
             self._createNetworkManager()
-        assert (self._manager is not None)
+        assert self._manager is not None
 
     ##  Callback for when the network manager detects that authentication is required but was not given.
     @staticmethod

cura/PrinterOutput/NetworkedPrinterOutputDevice.py

@@ -1,22 +1,18 @@
 # Copyright (c) 2018 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
-
-from UM.FileHandler.FileHandler import FileHandler #For typing.
-from UM.Logger import Logger
-from UM.Scene.SceneNode import SceneNode #For typing.
-from cura.CuraApplication import CuraApplication
-from cura.NetworkClient import NetworkClient
-
-from cura.PrinterOutputDevice import PrinterOutputDevice, ConnectionState
-
-from PyQt5.QtNetwork import QHttpMultiPart, QHttpPart, QNetworkRequest, QNetworkAccessManager, QNetworkReply, QAuthenticator
-from PyQt5.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject, QUrl, QCoreApplication
+import os
+import gzip
 from time import time
-from typing import Any, Callable, Dict, List, Optional
+from typing import Dict, List, Optional
 from enum import IntEnum
 
-import os  # To get the username
-import gzip
+from PyQt5.QtNetwork import QNetworkRequest, QNetworkReply
+from PyQt5.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject, QCoreApplication
+
+from UM.FileHandler.FileHandler import FileHandler
+from UM.Scene.SceneNode import SceneNode
+from cura.NetworkClient import NetworkClient
+from cura.PrinterOutputDevice import PrinterOutputDevice, ConnectionState
 
 
 class AuthState(IntEnum):