Accessor tries to create an extensionsv1alpha1.Object from the given runtime.Object.
If the given object already implements object, it is returned as-is. If the object is unstructured, an unstructured accessor is returned that retrieves values on a best-effort basis. Otherwise, an error with the type of the object is returned.
UnstructuredAccessor is an Object that retrieves values on a best-effort basis. If values don't exist, it usually returns the zero value of them.