function memoizeCapped(func) {
  var result = memoize(func, function(key) {
    if (cache.size === MAX_MEMOIZE_SIZE) {
      cache.clear();
    }
    return key;
  });

  var cache = result.cache;
  return result;
}
A specialized version of `_.memoize` which clears the memoized function's
cache when it exceeds `MAX_MEMOIZE_SIZE`.

@private
@param {Function} func The function to have its output memoized.
@returns {Function} Returns the new memoized function.