code: def test_get_dir_derivs(self):
      cav = np.array([[1, 2, 3]])
      dataset_outputs = [
          {
              "probas": [0.2, 0.8],
              "cls_grad": [3, 2, 1],
              "grad_class": "1",
          },
          {
              "probas": [0.6, 0.4],
              "cls_grad": [1, 2, 0],
              "grad_class": "0",
          },
      ]
      # Example where only the first output is in class_to_explain 1.
      dir_derivs = self.tcav.get_dir_derivs(
          cav,
          dataset_outputs,
          "cls_grad",
          "grad_class",
          class_to_explain="1",
      )
      self.assertListEqual([10], dir_derivs)
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  from lit_nlp.api import dataset
  from lit_nlp.api import model
  from lit_nlp.api import types
  from lit_nlp.components import tcav
  import numpy
label_desc: Use image node_id 7 for calling the TCAVTest obj's underlying member method code with example usage: obj.test_get_dir_derivs() without return types