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: 20220331093754_fix_development_encoding_issues.rb
    path of file: ./repos/sequencescape/db/migrate
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

# The default database encoding for the development database was wrong
# We've fixed it up for newly created databases, but 
    
  def update_tables
    change_encoding('bkp_lab_events', from: 'utf8', to: 'utf8mb4')
    change_encoding('isndc_countries', from: 'utf8', to: 'utf8mb4')
    change_encoding('pick_lists', from: 'utf8', to: 'utf8mb4')
    change_encoding('racked_tubes', from: 'utf8', to: 'utf8mb4')
    change_encoding('sample_compounds_components', from: 'utf8', to: 'utf8mb4')
    change_encoding('tube_rack_statuses', from: 'utf8', to: 'utf8mb4')
  end