code: def assertValidProjection(
      self, metadata_field, expected_image_path=None
  ):
      self.assertTrue(os.path.exists(metadata_field.filepath))
      self.assertGreater(os.path.getsize(metadata_field.filepath), 0)
  
      if expected_image_path:
          expected_image = Image.open(expected_image_path)
          actual_image = Image.open(metadata_field.filepath)
          self.assertTrue(
              np.array_equal(
                  np.array(expected_image), np.array(actual_image)
              )
          )
  
imports: import os
  import tempfile
  import unittest
  import numpy
  import open3d
  from PIL import Image
  import fiftyone
  import fiftyone.utils.utils3d
  from decorators import drop_datasets
label_desc: Use image node_id 3 for calling the BaseOrthographicProjectionTests obj's underlying member method code with example usage: obj.assertValidProjection(metadata_field, expected_image_path) without return types