Unsafe cast in PyObject.getAttribute(…, Class)

[desruisseaux]

Javadoc of the following method said that it accepts null value for the valueType argument:

public <T> T getAttribute(String name, Class<? extends T> valueType);

However there is no way this method can be type-safe with a null valueType. For example the following code compile without errors even if the "recipe" attribute is not an Integer:

Integer recipe = obj.getAttribute("recipe", null);

This can be fixed by:

• Disallowing null Class argument value in T getAttribute(String, Class).
• Adding a Object getAttribute(String) method in replacement for the case where the Class argument was null.

On a related topic, I don't see where getAttribute(String, Class) verifies the type. Is it done in the native code? If not, then we should add a valueType.cast(theResult) call in the method implementation.