function hashDelete(key) {
  var result = this.has(key) && delete this.__data__[key];
  this.size -= result ? 1 : 0;
  return result;
}
Removes `key` and its value from the hash.

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