code: function findFunctions(optionFunctions, defaultDir) {
    var allFunctions = [];
    optionFunctions = toArray(optionFunctions);
    optionFunctions.forEach(function (fn, i) {
      if (typeof fn === 'function') {
        allFunctions.push(fn);
        return;
      }
      if (typeof fn !== 'string') {
        throw new Error('function must be a string or array');
      }
      var m = requireMaybe(fn);
      if (!m) {
        m = requireMaybe(path.join(process.cwd(), fn));
      }
      if (!m) {
        m = requireMaybe(path.join('..', defaultDir, fn));
      }
      if (!m) {
        throw new Error('did not find function or problem loading function: ' + fn);
      }
      if (typeof m !== 'function') {
        throw new Error('function module must export a function');
      }
      allFunctions.push(m);
    });
    return allFunctions;
  }
docs: /*
  Require the specified function modules, either in the default location or
  the user-specified location.
  @param {Array|string}  Possible modules to find.
  @param {string} Default location to look for modules.