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: redmine-backporter.rb
    path of file: ./repos/jruby/test/tool
    
    the code of the file until where you have to start completion: #!/usr/bin/env ruby
require 'open-uri'
require 'openssl'
require 'net/http'
require 'json'
require 'io/console'
require 'stringio'
require 'strscan'
require 'optparse'
require 'abbr
    
def backport_command_string
  unless @changesets.respond_to?(:validated)
    @changesets = @changesets.select do |c|
      next false if c.match(/\A\d{1,6}\z/) # skip SVN revision

      # check if the Git revision is included in trunk
      begin
        uri = URI("#{REDMINE_BASE}/projects/ruby-master/repository/git/revisions/#{c}")
        uri.read($openuri_options)
        true
      rescue
        false
      end
    end