enumerate_support(expand=True)
  Returns tensor containing all values supported by a discrete
  distribution. The result will enumerate over dimension 0, so the
  shape of the result will be *(cardinality,) + batch_shape +
  event_shape* (where *event_shape = ()* for univariate
  distributions).

  Note that this enumerates over all batched tensors in lock-step
  *[[0, 0], [1, 1], ...]*. With *expand=False*, enumeration
  happens along dim 0, but with the remaining batch dimensions
  being singleton dimensions, *[[0], [1], ..*.

  To iterate over the full Cartesian product use
  *itertools.product(m.enumerate_support())*.

  Parameters:
     **expand** (*bool*) -- whether to expand the support over the
     batch dims to match the distribution's *batch_shape*.

  Returns:
     Tensor iterating over dimension 0.

  Return type:
     *Tensor*

property event_shape: Size
  Returns the shape of a single sample (without batching).
