code: def testModeEnableAllowNanStats(self):
      alpha = np.array([1.0, 2, 3])
      dist = dirichlet.Dirichlet(
          concentration=alpha, allow_nan_stats=True
      )
      expected_mode = np.zeros_like(alpha) + np.nan
  
      self.assertAllEqual([3], dist.mode().shape)
      self.assertAllClose(expected_mode, self.evaluate(dist.mode()))
  
imports: import numpy
  from scipy import special
  from scipy import stats
  import tensorflow.compat.v2
  from tensorflow_probability.python.bijectors import exp
  from tensorflow_probability.python.distributions import dirichlet
  from tensorflow_probability.python.distributions import kullback_leibler
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math import gradient
  from tensorflow_probability.python.util import deferred_tensor
label_desc: Use image node_id 19 for calling the DirichletTest obj's underlying member method code with example usage: obj.testModeEnableAllowNanStats() without return types