@if minimum_version(3.20)
body members foo
{
  include => { "alice", "bob" };
  exclude => { "malcom" };
}
@endif

@if minimum_version(3.20)
promise agent blah
{
  path => "/some/path";
}
@endif

bundle agent __main__
{
  groups:
    "foo"
      policy => "present",
@if minimum_version(3.20)
      members => foo;
@else
      members => '{ "include": ["alice", "bob"],
                    "exclude": ["malcom"] }';
@endif
}