module ActiveJob::QueueAdapter::ClassMethods

def assign_adapter(adapter_name, queue_adapter) 

def assign_adapter(adapter_name, queue_adapter)
  self._queue_adapter_name = adapter_name
  self._queue_adapter = queue_adapter
end

def queue_adapter

is the +:async+ queue. See QueueAdapters for more information.
Returns the backend queue provider. The default queue adapter 
def queue_adapter
  _queue_adapter
end

def queue_adapter=(name_or_adapter)

information.
is the +:async+ queue. See QueueAdapters for more
Specify the backend queue provider. The default queue adapter 
def queue_adapter=(name_or_adapter)
  case name_or_adapter
  when Symbol, String
    queue_adapter = ActiveJob::QueueAdapters.lookup(name_or_adapter).new
    assign_adapter(name_or_adapter.to_s, queue_adapter)
  else
    if queue_adapter?(name_or_adapter)
      adapter_name = "#{name_or_adapter.class.name.demodulize.remove('Adapter').underscore}"
      assign_adapter(adapter_name, name_or_adapter)
    else
      raise ArgumentError
    end
  end
end

def queue_adapter?(object) 

def queue_adapter?(object)
  QUEUE_ADAPTER_METHODS.all? { |meth| object.respond_to?(meth) }
end

def queue_adapter_name

By default returns "async".
Returns string denoting the name of the configured queue adapter. 
def queue_adapter_name
  _queue_adapter_name
end