feat: Add idempotency key to session creation requests (#1327)

Author: mykola-mokhnach

src/main/java/io/appium/java_client/remote/AppiumCommandExecutor.java

@@ -62,8 +62,11 @@
 import java.net.URL;
 import java.util.Map;
 import java.util.Optional;
+import java.util.UUID;
 
 public class AppiumCommandExecutor extends HttpCommandExecutor {
+    // https://github.com/appium/appium-base-driver/pull/400
+    private static final String IDEMPOTENCY_KEY_HEADER = "X-Idempotency-Key";
 
     private final Optional<DriverService> serviceOptional;
 
@@ -150,18 +153,23 @@ protected void setResponseCodec(ResponseCodec<HttpResponse> codec) {
     }
 
     protected HttpClient getClient() {
-        //noinspection unchecked
         return getPrivateFieldValue("client", HttpClient.class);
     }
 
+    protected HttpClient withRequestsPatchedByIdempotencyKey(HttpClient httpClient) {
+        return (request) -> {
+            request.setHeader(IDEMPOTENCY_KEY_HEADER, UUID.randomUUID().toString().toLowerCase());
+            return httpClient.execute(request);
+        };
+    }
+
     private Response createSession(Command command) throws IOException {
         if (getCommandCodec() != null) {
             throw new SessionNotCreatedException("Session already exists");
         }
         ProtocolHandshake handshake = new ProtocolHandshake() {
-            @SuppressWarnings("unchecked")
-            public Result createSession(HttpClient client, Command command)
-                    throws IOException {
+            @SuppressWarnings({"unchecked", "UnstableApiUsage"})
+            public Result createSession(HttpClient client, Command command) throws IOException {
                 Capabilities desiredCapabilities = (Capabilities) command.getParameters().get("desiredCapabilities");
                 Capabilities desired = desiredCapabilities == null ? new ImmutableCapabilities() : desiredCapabilities;
 
@@ -182,8 +190,8 @@ public Result createSession(HttpClient client, Command command)
                                 .getDeclaredMethod("createSession", HttpClient.class, InputStream.class, long.class);
                         createSessionMethod.setAccessible(true);
 
-                        Optional<Result> result = (Optional<Result>) createSessionMethod
-                                .invoke(this, client, contentStream, counter.getCount());
+                        Optional<Result> result = (Optional<Result>) createSessionMethod.invoke(this,
+                                withRequestsPatchedByIdempotencyKey(client), contentStream, counter.getCount());
 
                         return result.map(result1 -> {
                             Result toReturn = result.get();