code: def test_frame_accuracy_all_background(self):
      logits = np.array(
          [
              [1.5, 0.0, -1.0],
              [0.1, 0.7, 0.2],
              [0.1, 0.7, 0.2],
              [0.1, -0.7, 0.2],
              [-0.1, -0.7, -0.2],
          ],
          np.float32,
      )
      label = np.array(
          [
              [0, 0, 0],
              [0, 0, 0],
              [0, 0, 0],
              [0, 0, 0],
              [0, 0, 0],
          ],
          np.int32,
      )
      actual = metrics.frame_accuracy(logits, label)
      self.assertAlmostEqual(actual, 0.2)
  
file_path: scenic/scenic/projects/unloc/metrics_test.py
imports: from absl.testing import parameterized
  import numpy
  from scenic.projects.unloc import metrics
  import tensorflow
label_desc: Use image node_id 2 for calling the MetricsTest obj's underlying member method code with example usage: obj.test_frame_accuracy_all_background() without return types