code: def test_encode_array_to_base64(self):
      img = Image.open("gradio/test_data/test_image.png")
      img = img.convert("RGB")
      numpy_data = np.asarray(img, dtype=np.uint8)
      output_base64 = processing_utils.encode_array_to_base64(
          numpy_data
      )
      assert output_base64 == deepcopy(media_data.ARRAY_TO_BASE64_IMAGE)
  
imports: import os
  import shutil
  import tempfile
  from copy import deepcopy
  from pathlib import Path
  from unittest.mock import patch
  import ffmpy
  import numpy
  import pytest
  from gradio_client import media_data
  from PIL import Image, ImageCms
  from gradio import processing_utils, utils
label_desc: Use image node_id 2 for calling the TestImagePreprocessing obj's underlying member method code with example usage: obj.test_encode_array_to_base64() without return types