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: rake_tasks.rb
    path of file: ./repos/padrino-framework/padrino-core/lib/padrino-core/cli
    
    the code of the file until where you have to start completion: # Loads the Padrino applications mounted within the project.
# 
    
def env_migration_version
  version = ENV["MIGRATION_VERSION"]
  if version.nil? && ENV["VERSION"]
    deprecated = true
    warn "Environment variable VERSION is deprecated, use MIGRATION_VERSION"
    version = ENV["VERSION"]
  end