# File lib/redis.rb, line 477
  def migrate(key, options)
    host = options[:host] || raise(RuntimeError, ":host not specified")
    port = options[:port] || raise(RuntimeError, ":port not specified")
    db = (options[:db] || client.db).to_i
    timeout = (options[:timeout] || client.timeout).to_i

    synchronize do |client|
      client.call([:migrate, host, port, key, db, timeout])
    end
  end