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: missing_formula.rb
    path of file: ./repos/brew/Library/Homebrew
    
    the code of the file until where you have to start completion: require "formulary"

module Homebrew
  module MissingFormula
    class << self
      def reason(name, silent: false)
        blacklisted_reason(name) || tap_migration_reason(name) ||
          deleted_reason(name, silent: silent)
      end

      def blacklisted
    
      def deleted_reason(name, silent: false)
        path = Formulary.path name
        return if File.exist? path

        tap = Tap.from_path(path)
        return if tap.nil? || !File.exist?(tap.path)

        relative_path = path.relative_path_from tap.path

        tap.path.cd do
          unless silent
            ohai "Searching for a previously deleted formula (in the last month)..."
            if (tap.path/".git/shallow").exist?
              opoo <<~EOS
                #{tap} is shallow clone. To get complete history run:
                  git -C "$(brew --repo #{tap})" fetch --unshallow

              EOS
            end
          end