concat() assertions around input shape/datatypes seem invalid

[inexorabletash]

The MLGraphBuilder concat(sequence<MLOperand> inputs, unsigned long axis) method has:

Assert: the shape, i.e. dimensions of each operand in inputs is the same, except on the dimension given by axis on which they are concatenated.
Assert: the dataType of each operand in inputs is the same.

Since the inputs are provided by script, these don't seem to be invariants. Are these intended to be validation steps instead?