class_docstr: Transforms vectors to triangular.
  
  Triangular matrix elements are filled in a clockwise spiral.
  
  Given input with shape `batch_shape + [d]`, produces output with
  shape `batch_shape + [n, n]`, where
   `n = (-1 + sqrt(1 + 8 * d))/2`.
  This follows by solving the quadratic equation
   `d = 1 + 2 + ... + n = n * (n + 1)/2`.
  
  #### Example
  
  ```python
  b = tfb.FillTriangular(upper=False)
  b.forward([1, 2, 3, 4, 5, 6])
  # ==> [[4, 0, 0],
  #      [6, 5, 0],
  #      [3, 2, 1]]
  
  b = tfb.FillTriangular(upper=True)
  b.forward([1, 2, 3, 4, 5, 6])
  # ==> [[1, 2, 3],
  #      [0, 5, 6],
  #      [0, 0, 4]]
  
  ```
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code: def _forward_log_det_jacobian(self, x):
      return tf.zeros([], dtype=x.dtype)
  
imports: import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.bijectors import bijector
  from tensorflow_probability.python.internal import assert_util
  from tensorflow_probability.python.internal import tensorshape_util
  from tensorflow_probability.python.math.linalg import fill_triangular
  from tensorflow_probability.python.math.linalg import fill_triangular_inverse
label_desc: Use image node_id 5 for calling the FillTriangular obj's underlying member method code with example usage: obj._forward_log_det_jacobian(x) and returns: tf