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: lttb_sinatra.rb
    path of file: ./repos/timescaledb/examples/toolkit-demo/lttb
    
    the code of the file until where you have to start completion: # ruby lttb.rb postgres://user:pass@host:port/db_name
require 'bundler/inline' #require only what you need

gemfile(true) do
  gem 'timescaledb', path:  '../../..'
  gem 'pry'
  gem 'sinatra', require: false
  gem
    
def setup size: :small
  file = "weather_#{size}.tar.gz"
  download_weather_dataset(size: size) unless File.exists? file
  puts "extracting #{file}"
  system "tar -xvzf #{file} "
  puts "creating data structures"
  system "psql #{PG_URI} < weather.sql"
  system %|psql #{PG_URI} -c "\\COPY locations FROM weather_#{size}_locations.csv CSV"|
  system %|psql #{PG_URI} -c "\\COPY conditions FROM weather_#{size}_conditions.csv CSV"|
end