code: def embed_coords(self, coords):
      # Use logit embedding.
      logits = tf.concat(
          [coords, tf.zeros_like(coords[..., -1:])], axis=-1
      )
      return tf.nn.softmax(logits)
  
imports: from absl.testing import parameterized
  import numpy
  import scipy.special
  import tensorflow.compat.v2
  from tensorflow_probability.python.bijectors import exp
  from tensorflow_probability.python.bijectors import identity
  from tensorflow_probability.python.bijectors import scale
  from tensorflow_probability.python.bijectors import scale_matvec_tril
  from tensorflow_probability.python.experimental.tangent_spaces import simplex
  from tensorflow_probability.python.experimental.tangent_spaces import spaces_test_util
  from tensorflow_probability.python.internal import test_util
label_desc: Use image node_id 2 for calling the _SimplexTest obj's underlying member method code with example usage: obj.embed_coords(coords) and returns: tf