Added some instance checks

core.lua

@@ -8,6 +8,10 @@ function Core:new()
 end
 
 function Core:connect()
+    if not self then
+        error("No instance!")
+    end
+
     ws, err = assert(http.websocket("ws://192.168.5.162:8080"));
 
     if not ws then
@@ -20,6 +24,10 @@ function Core:connect()
 end
 
 function Core:send(package)
+    if not self then
+        error("No instance!")
+    end
+
     if not package then
         return false, "Missing package";
     end
@@ -32,14 +40,22 @@ function Core:send(package)
 end
 
 function Core:read()
+    if not self then
+        error("No instance!")
+    end
+    
     if not self.ws then
         return false, "Websocket not initiated";
     end
 
-    return true, textutils.unserialiseJSON(self.ws.read())
+    return true, textutils.unserialiseJSON(self.ws.receive())
 end
 
 function Core:download(file)
+    if not self then
+        error("No instance!")
+    end
+    
     if not self.ws then
         return false, "Websocket not initiated";
     end