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: similarity_detector.rb
    path of file: ./repos/truffleruby/lib/mri/bundler
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Bundler
  class SimilarityDetector
    SimilarityScore = Struct.new(:string, :distance)

    # initialize with an array of words to be matched against
    def initialize(corpus)
      @corpus = corpus
    end

    # return an array of words similar to 'word' from the corpus
    def similar_words(word, limit = 3)
      words_by_similarity = @corpus.map {|w| Similar
    
    def levenshtein_distance(this, that, ins = 2, del = 2, sub = 1)
      # ins, del, sub are weighted costs
      return nil if this.nil?
      return nil if that.nil?
      dm = [] # distance matrix

      # Initialize first row values
      dm[0] = (0..this.length).collect {|i| i * ins }
      fill = [0] * (this.length - 1)

      # Initialize first column values
      (1..that.length).each do |i|
        dm[i] = [i * del, fill.flatten]
      end

      # populate matrix
      (1..that.length).each do |i|
        (1..this.length).each do |j|
          # critical comparison
          dm[i][j] = [
            dm[i - 1][j - 1] + (this[j - 1] == that[i - 1] ? 0 : sub),
            dm[i][j - 1] + ins,
            dm[i - 1][j] + del,
          ].min
        end
      end

      # The last value in matrix is the Levenshtein distance between the strings
      dm[that.length][this.length]
    end