module ActiveRecord::Migration::Compatibility

def self.find(version)
  version = version.to_s
  name = "V#{version.tr('.', '_')}"
  unless const_defined?(name)
    versions = constants.grep(/\AV[0-9_]+\z/).map { |s| s.to_s.delete("V").tr("_", ".").inspect }
    raise ArgumentError, "Unknown migration version #{version.inspect}; expected one of #{versions.sort.join(', ')}"
  end
  const_get(name)
end