Gemini Backend (#9)

Co-authored-by: Ying Sheng <sqy1415@gmail.com>

examples/quick_start/gemini_example_multimodal_chat.py

@@ -0,0 +1,19 @@
+from sglang import function, user, assistant, gen, image, set_default_backend, Gemini
+
+
+@function
+def image_qa(s, image_file1, image_file2, question):
+    s += user(image(image_file1) + image(image_file2) + question)
+    s += assistant(gen("answer_1", max_tokens=256))
+
+set_default_backend(Gemini("gemini-pro-vision"))
+
+state = image_qa.run(
+    image_file1="./images/cat.jpeg",
+    image_file2="./images/dog.jpeg",
+    question="Describe difference of the 2 images in one sentence.",
+    stream=True
+)
+
+for out in state.text_iter():
+    print(out, end="", flush=True)