diff --git a/src/display/network.js b/src/display/network.js
index 892acbb37..145772c72 100644
--- a/src/display/network.js
+++ b/src/display/network.js
@@ -43,11 +43,10 @@ function getArrayBuffer(xhr) {
 }
 
 class NetworkManager {
-  constructor(url, args) {
+  constructor(url, args = {}) {
     this.url = url;
-    args = args || {};
     this.isHttp = /^https?:/i.test(url);
-    this.httpHeaders = (this.isHttp && args.httpHeaders) || {};
+    this.httpHeaders = (this.isHttp && args.httpHeaders) || Object.create(null);
     this.withCredentials = args.withCredentials || false;
     this.getXhr =
       args.getXhr ||
@@ -77,9 +76,7 @@ class NetworkManager {
   request(args) {
     const xhr = this.getXhr();
     const xhrId = this.currXhrId++;
-    const pendingRequest = (this.pendingRequests[xhrId] = {
-      xhr,
-    });
+    const pendingRequest = (this.pendingRequests[xhrId] = { xhr });
 
     xhr.open("GET", this.url);
     xhr.withCredentials = this.withCredentials;
@@ -119,20 +116,15 @@ class NetworkManager {
   onProgress(xhrId, evt) {
     const pendingRequest = this.pendingRequests[xhrId];
     if (!pendingRequest) {
-      // Maybe abortRequest was called...
-      return;
-    }
-
-    if (pendingRequest.onProgress) {
-      pendingRequest.onProgress(evt);
+      return; // Maybe abortRequest was called...
     }
+    pendingRequest.onProgress?.(evt);
   }
 
   onStateChange(xhrId, evt) {
     const pendingRequest = this.pendingRequests[xhrId];
     if (!pendingRequest) {
-      // Maybe abortRequest was called...
-      return;
+      return; // Maybe abortRequest was called...
     }
 
     const xhr = pendingRequest.xhr;
@@ -155,9 +147,7 @@ class NetworkManager {
 
     // Success status == 0 can be on ftp, file and other protocols.
     if (xhr.status === 0 && this.isHttp) {
-      if (pendingRequest.onError) {
-        pendingRequest.onError(xhr.status);
-      }
+      pendingRequest.onError?.(xhr.status);
       return;
     }
     const xhrStatus = xhr.status || OK_RESPONSE;
@@ -173,9 +163,7 @@ class NetworkManager {
       !ok_response_on_range_request &&
       xhrStatus !== pendingRequest.expectedStatus
     ) {
-      if (pendingRequest.onError) {
-        pendingRequest.onError(xhr.status);
-      }
+      pendingRequest.onError?.(xhr.status);
       return;
     }
 
@@ -192,8 +180,8 @@ class NetworkManager {
         begin: 0,
         chunk,
       });
-    } else if (pendingRequest.onError) {
-      pendingRequest.onError(xhr.status);
+    } else {
+      pendingRequest.onError?.(xhr.status);
     }
   }
 
@@ -256,9 +244,8 @@ class PDFNetworkStream {
   }
 
   cancelAllRequests(reason) {
-    if (this._fullRequestReader) {
-      this._fullRequestReader.cancel(reason);
-    }
+    this._fullRequestReader?.cancel(reason);
+
     for (const reader of this._rangeRequestReaders.slice(0)) {
       reader.cancel(reason);
     }
@@ -332,13 +319,13 @@ class PDFNetworkStreamFullRequestReader {
     this._headersReceivedCapability.resolve();
   }
 
-  _onDone(args) {
-    if (args) {
+  _onDone(data) {
+    if (data) {
       if (this._requests.length > 0) {
         const requestCapability = this._requests.shift();
-        requestCapability.resolve({ value: args.chunk, done: false });
+        requestCapability.resolve({ value: data.chunk, done: false });
       } else {
-        this._cachedChunks.push(args.chunk);
+        this._cachedChunks.push(data.chunk);
       }
     }
     this._done = true;
@@ -352,24 +339,20 @@ class PDFNetworkStreamFullRequestReader {
   }
 
   _onError(status) {
-    const url = this._url;
-    const exception = createResponseStatusError(status, url);
-    this._storedError = exception;
-    this._headersReceivedCapability.reject(exception);
+    this._storedError = createResponseStatusError(status, this._url);
+    this._headersReceivedCapability.reject(this._storedError);
     for (const requestCapability of this._requests) {
-      requestCapability.reject(exception);
+      requestCapability.reject(this._storedError);
     }
     this._requests.length = 0;
     this._cachedChunks.length = 0;
   }
 
-  _onProgress(data) {
-    if (this.onProgress) {
-      this.onProgress({
-        loaded: data.loaded,
-        total: data.lengthComputable ? data.total : this._contentLength,
-      });
-    }
+  _onProgress(evt) {
+    this.onProgress?.({
+      loaded: evt.loaded,
+      total: evt.lengthComputable ? evt.total : this._contentLength,
+    });
   }
 
   get filename() {
@@ -440,9 +423,7 @@ class PDFNetworkStreamRangeRequestReader {
   }
 
   _close() {
-    if (this.onClosed) {
-      this.onClosed(this);
-    }
+    this.onClosed?.(this);
   }
 
   _onDone(data) {
@@ -462,10 +443,8 @@ class PDFNetworkStreamRangeRequestReader {
   }
 
   _onProgress(evt) {
-    if (!this.isStreamingSupported && this.onProgress) {
-      this.onProgress({
-        loaded: evt.loaded,
-      });
+    if (!this.isStreamingSupported) {
+      this.onProgress?.({ loaded: evt.loaded });
     }
   }