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: medium_providers_registry.rb
    path of file: ./repos/foreman/app/registries/foreman/plugin
    
    the code of the file until where you have to start completion: module Foreman
  class Plugin
    # This class is used to store list of medium uri providers that are responsible to supply
    # locations of installation medium in form of URI.
    # This is used by provisioning framework to supply download location for various files
    # used during the provisioning.
    class MediumProvidersRegistry
      delegate :logger, to: Rails
      attr_reader :providers

      def initialize
        @providers = []
      end

      # Register a new medium_u
    
      def find_provider(entity)
        raise Foreman::Exception.new('Must supply an entity to find a medium provider') unless entity

        provider_instances = providers.map { |provider| provider.constantize.new(entity) }
        valid_providers = provider_instances.select { |provider| provider.valid? }
        if valid_providers.count > 1
          logger.error(
            'Found more than one provider for %{entity}. Found: %{found}. Valid providers: %{providers}' %
            {
              entity: entity,
              providers: providers.map { |provider| provider.class.name },
              found: valid_providers.map { |provider| provider.class.name },
            })
        end