function defineWarningProperty(object, key) {
  Object.defineProperty(object, key, {

    configurable: false,
    enumerable: true,

    get: function() {
      if (!this._store) {
        return null;
      }
      return this._store[key];
    },

    set: function(value) {
      ("production" !== process.env.NODE_ENV ? warning(
        false,
        'Don\'t set the ' + key + ' property of the component. ' +
        'Mutate the existing props object instead.'
      ) : null);
      this._store[key] = value;
    }

  });
}
Warn for mutations.

@internal
@param {object} object
@param {string} key