Document AssertNextDataset op
diff --git a/tensorflow/core/api_def/base_api/api_def_AssertNextDataset.pbtxt b/tensorflow/core/api_def/base_api/api_def_AssertNextDataset.pbtxt
index c97b807..c1ad34a 100644
--- a/tensorflow/core/api_def/base_api/api_def_AssertNextDataset.pbtxt
+++ b/tensorflow/core/api_def/base_api/api_def_AssertNextDataset.pbtxt
@@ -1,4 +1,30 @@
op {
graph_op_name: "AssertNextDataset"
visibility: HIDDEN
+ in_arg {
+ name: "input_dataset"
+ description: <<END
+A variant tensor representing the input dataset.
+`AssertNextDataset` passes through the outputs of its input dataset.
+END
+ }
+ in_arg {
+ name: "transformations"
+ description: <<END
+A `tf.string` vector `tf.Tensor` identifying the transformations that are
+expected to happen next.
+END
+ }
+ summary: "A transformation that asserts which transformations happen next."
+ 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.
+END
}
