check_stvar: Checks whether the given object has class attribute 'stvar'
Description
check_stvar
checks that the object has class attribute 'stvar'.
Usage
check_stvar(object, object_name)
Value
Throws an error if the object doesn't have the class attribute 'stvar'.
Arguments
- object
S3 object to be tested
- object_name
what is the name of the object that should of class 'stvar'?