Log warning when given wrong type.

Author: mrober

transport/transport-runtime/src/main/java/com/google/android/datatransport/runtime/ForcedSender.java

@@ -14,21 +14,28 @@
 
 package com.google.android.datatransport.runtime;
 
+import android.annotation.SuppressLint;
 import androidx.annotation.Discouraged;
 import androidx.annotation.WorkerThread;
 import com.google.android.datatransport.Priority;
 import com.google.android.datatransport.Transport;
+import com.google.android.datatransport.runtime.logging.Logging;
 
 @Discouraged(
     message =
         "TransportRuntime is not a realtime delivery system, don't use unless you absolutely must.")
 public final class ForcedSender {
+  private static final String LOG_TAG = "ForcedSender";
+
+  @SuppressLint("DiscouragedApi")
   @WorkerThread
   public static void sendBlocking(Transport<?> transport, Priority priority) {
     if (transport instanceof TransportImpl) {
       TransportContext context =
           ((TransportImpl<?>) transport).getTransportContext().withPriority(priority);
       TransportRuntime.getInstance().getUploader().logAndUpdateState(context, 1);
+    } else {
+      Logging.w(LOG_TAG, "Expected instance of `TransportImpl`, got `%s`.", transport);
     }
   }