function cond(pairs) {
      var length = pairs == null ? 0 : pairs.length,
          toIteratee = getIteratee();

      pairs = !length ? [] : arrayMap(pairs, function(pair) {
        if (typeof pair[1] != 'function') {
          throw new TypeError(FUNC_ERROR_TEXT);
        }
        return [toIteratee(pair[0]), pair[1]];
      });

      return baseRest(function(args) {
        var index = -1;
        while (++index < length) {
          var pair = pairs[index];
          if (apply(pair[0], this, args)) {
            return apply(pair[1], this, args);
          }
        }
      });
    }
Creates a function that iterates over `pairs` and invokes the corresponding
function of the first predicate to return truthy. The predicate-function
pairs are invoked with the `this` binding and arguments of the created
function.

@static
@memberOf _
@since 4.0.0
@category Util
@param {Array} pairs The predicate-function pairs.
@returns {Function} Returns the new composite function.
@example

var func = _.cond([
  [_.matches({ 'a': 1 }),           _.constant('matches A')],
  [_.conforms({ 'b': _.isNumber }), _.constant('matches B')],
  [_.stubTrue,                      _.constant('no match')]
]);

func({ 'a': 1, 'b': 2 });
// => 'matches A'

func({ 'a': 0, 'b': 1 });
// => 'matches B'

func({ 'a': '1', 'b': '2' });
// => 'no match'