True if argObj is of a suitable type for specifying a component’s index. False otherwise.
Dicts allow for components whose ‘mel name’ may vary - ie, a single isoparm component may have, u, v, or uv elements; or, a single pivot component may have scalePivot and rotatePivot elements. The key of the dict would indicate the ‘mel component name’, and the value the actual indices.
Derived classes should implement: _dimLength