'Determine if value is empty in the context of this property.
For most kinds, this is equivalent to "not value", but for kinds like
bool, the test is more subtle, so subclasses can override this method
if necessary.
Args:
value: Value to validate against this Property.
Returns:
True if this value is considered empty in the context of this Property
type, otherwise False.'

def empty(self, value):

    return (not value)
