includeConditionalArg = function includeConditionalArg(argType, args, globals) {
  if (!argType["if"]) return true;
  var _ref2 = argType["if"],
      arg = _ref2.arg,
      global = _ref2.global;

  if (count([arg, global]) !== 1) {
    throw new Error("Invalid conditional value ".concat(JSON.stringify({
      arg: arg,
      global: global
    })));
  }

  var value = arg ? args[arg] : globals[global];
  return testValue(argType["if"], value);
}
Helper function to include/exclude an arg based on the value of other other args
aka "conditional args"