class_docstr: Computes the cumulative sum of a tensor along a specified axis.
  
  If `axis` is not provided, the default uses the rightmost dimension, i.e.,
  axis=-1.
  
  #### Example
  
  ```python
  x = tfb.Cumsum()
  
  x.forward([[1., 1.],
             [2., 2.],
             [3., 3.]])
  # ==> [[1., 2.],
         [2., 4.],
         [3., 6.]]
  
  x = tfb.Cumsum(axis=-2)
  
  x.forward([[1., 1.],
             [2., 2.],
             [3., 3.]])
  # ==> [[1., 1.],
         [3., 3.],
         [6., 6.]]
  ```
code: def _forward(self, x):
      return tf.cumsum(x, axis=self.axis)
  
file_path: probability/tensorflow_probability/python/bijectors/cumsum.py
imports: import tensorflow.compat.v2
  from tensorflow_probability.python.bijectors import bijector
  from tensorflow_probability.python.internal import prefer_static
label_desc: Use image node_id 4 for calling the Cumsum obj's underlying member method code with example usage: obj._forward(x) and returns: tf