Commander.js display help when called with no commands

I'm using commander.js to write a simple node.js program that interacts with an API. All calls require the use of subcommands. For example:

apicommand get

Is called as follows:

program
  .version('1.0.0')
  .command('get [accountId]')
  .description('retrieves account info for the specified account')
  .option('-v, --verbose', 'display extended logging information')
  .action(getAccount);

What I want to do now is display a default message when apicommand is called without any subcommands. Just like when you call git without a subcommand:

MacBook-Air:Desktop username$ git
usage: git [--version] [--help] [-C <path>] [-c name=value]
       [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
       [-p | --paginate | --no-pager] [--no-replace-objects] [--bare]
       [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]
       <command> [<args>]

These are common Git commands used in various situations:

start a working area (see also: git help tutorial)
   clone      Clone a repository into a new directory
   init       Create an empty Git repository or reinitialize an existing one
...

via toddg