maintain V1 while we are moving into TF 2.0.
    *   Add dataset ops to the graph (or create kernels in Eager execution)
        during the python Dataset object creation instead doing it during
        Iterator creation time.
    *   Add support for TensorArrays to tf.data Dataset.
    *   Switching tf.data functions to use `defun`, providing an escape hatch to

def TF_ReduceJoinOp : TF_Op<"ReduceJoin", [Pure]> {
  let summary = "Joins a string Tensor across the given dimensions.";

  let description = [{
Computes the string join across dimensions in the given string Tensor of shape
`[\\(d_0, d_1, ..., d_{n-1}\\)]`.  Returns a new Tensor created by joining the input
strings with the given separator (default: empty string).  Negative indices are