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: query.rb
    path of file: ./repos/searchkick/lib/searchkick
    
    the code of the file until where you have to start completion: module Searchkick
  class Query
    include Enumerable
    extend Forwardable

    @@metric_aggs = [:avg, :cardinalit
    
    def params
      if options[:models]
        @index_mapping = {}
        Array(options[:models]).each do |model|
          # there can be multiple models per index name due to inheritance - see #1259
          (@index_mapping[model.searchkick_index.name] ||= []) << model
        end
      end