function Add(args) {
	    return _Merge.call(this, args) || this;
	  }
Computes the shape of the result of an elementwise operation.

@param shape1: Shape of the first tensor.
@param shape2: Shape of the second tensor.
@returns Expected output shape when an elementwise operation is carried
  out on 2 tensors with shapes `shape1` and `shape2`.
@throws ValueError: If `shape1` and `shape2` are not compatible for
  element-wise operations.