*   Added an easy way to add and dynamically load user-defined ops
*   Built out a good suite of tests, things should break less!
*   Added `MetaGraphDef` which makes it easier to save graphs with metadata
*   Added assignments for "Deep Learning with TensorFlow" udacity course

## Bug Fixes and Other Changes

*   Added a versioning framework for `GraphDef`s to ensure compatibility
*   Enforced Python 3 compatibility

  let hasCanonicalizer = 1;
}

def TF_AssignOp : TF_Op<"Assign", []> {
  let summary = "Update 'ref' by assigning 'value' to it.";

  let description = [{
This operation outputs "ref" after the assignment is done.
This makes it easier to chain operations that need to use the reset value.
  }];

  let arguments = (ins
    Arg<TF_Tensor, [{Should be from a `Variable` node. May be uninitialized.}]>:$ref,