message: Reword description per review comments
diff: @@ -19,12 +19,14 @@ END
  description: <<END
  Core C++ implementation of the transformation `assert_next()`, which is
  an internal component of `tf.data`'s Python API.
  -This transformation checks whether the Pascal-case names (i.e. "FlatMap", not
  -"flat_map") of the transformations immediately after it match the list of names
  -in the `transformations` argument. The transformation raises an exception if
  -it finds any discrepancies.
  -The check occurs immediately before iterating over the results of the
  -root dataset, which means that the check happens *after* any `tf.data`
  -optimizations or static optimizations are applied to the dataflow graph.
  +
  +This transformation checks whether the camel-case names (i.e. "FlatMap", not
  +"flat_map") of the transformations following this transformation match the list
  +of names in the `transformations` argument. If there is a mismatch, the
  +transformation raises an exception.
  +
  +The check occurs when iterating over the contents of the dataset, which
  +means that the check happens *after* any static optimizations are applied
  +to the dataset graph.
  END
  }
  