You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sequential_prioritizer.rb
    path of file: ./repos/puppet/lib/puppet/graph
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

# This implements a priority in which keys are given values that will keep them

    
  def generate_priority_contained_in(container, key)
    @container[container] ||= priority_of(container).down
    priority = @container[container].next
    record_priority_for(key, priority)
    @container[container] = priority
    priority
  end