def resolve_priority(pri)
      if pri.respond_to?(:queue_priority)
        resolve_priority(pri.queue_priority)
      elsif pri.is_a?(String) || pri.is_a?(Symbol) # named priority
        resolve_priority(Backburner.configuration.priority_labels[pri.to_sym])
      elsif pri.is_a?(Integer) # numerical
        pri
      else # default
        Backburner.configuration.default_priority
      end
    end
Resolves job priority based on the value given. Can be integer, a class or nothing

@example
resolve_priority(1000) => 1000
resolve_priority(FooBar) => <queue priority>
resolve_priority(nil) => <default priority>