function listCacheDelete(key) {
  var data = this.__data__,
      index = assocIndexOf(data, key);

  if (index < 0) {
    return false;
  }
  var lastIndex = data.length - 1;
  if (index == lastIndex) {
    data.pop();
  } else {
    splice.call(data, index, 1);
  }
  --this.size;
  return true;
}
Removes `key` and its value from the list cache.

@private
@name delete
@memberOf ListCache
@param {string} key The key of the value to remove.
@returns {boolean} Returns `true` if the entry was removed, else `false`.