Got at least one data fetching method working; turns out, we can't use a patched LogicStack to get the data

Vendor/EmbedIO-3.5.2/WebSockets/Opcode.cs

@@ -0,0 +1,43 @@
+namespace EmbedIO.WebSockets
+{
+    /// <summary>
+    /// Indicates the WebSocket frame type.
+    /// </summary>
+    /// <remarks>
+    /// The values of this enumeration are defined in
+    /// <see href="http://tools.ietf.org/html/rfc6455#section-5.2">
+    /// Section 5.2</see> of RFC 6455.
+    /// </remarks>
+    public enum Opcode : byte
+    {
+        /// <summary>
+        /// Equivalent to numeric value 0. Indicates continuation frame.
+        /// </summary>
+        Cont = 0x0,
+
+        /// <summary>
+        /// Equivalent to numeric value 1. Indicates text frame.
+        /// </summary>
+        Text = 0x1,
+
+        /// <summary>
+        /// Equivalent to numeric value 2. Indicates binary frame.
+        /// </summary>
+        Binary = 0x2,
+
+        /// <summary>
+        /// Equivalent to numeric value 8. Indicates connection close frame.
+        /// </summary>
+        Close = 0x8,
+
+        /// <summary>
+        /// Equivalent to numeric value 9. Indicates ping frame.
+        /// </summary>
+        Ping = 0x9,
+
+        /// <summary>
+        /// Equivalent to numeric value 10. Indicates pong frame.
+        /// </summary>
+        Pong = 0xa,
+    }
+}