module Resque

Usage:

class MyJob

def self.perform(arg1, arg2)
end
include Resque::Plugins::UniqueByArity.new(
  arity_for_uniqueness: 1,
  arity_validation: :warning, # or nil, false, or :error
  unique_at_runtime: true,
  unique_in_queue: true
)

end

NOTE: DO NOT include this module directly.

Use the Resque::Plugins::UniqueByArity approach as above.
This module is ultimately extended into the job class.