This method is just to support the compatibility with the previous version. It returns an ASM node of the
member on which the annotation is 'attached'. The type of the node depends on this element. It can be a FieldNode, a MethodNode or a
ClassNode. It actually checks the current node and returns the first set ones
in this order: field, method, class.
The type of the returned object can be determined using the getElementType() method. However it is
recommended to use one of the following method: getFieldNode(), getMethodNode() or