_onDelayedSearch (event) {
    // execute the search after a short delay (reduces the number of
    // search actions while typing in the search text box)
    this._clearDelay()
    const searchBox = this
    this.timeout = setTimeout(event => {
      searchBox._onSearch()
    }, this.delay)
  }
Start a timer to execute a search after a short delay.
Used for reducing the number of searches while typing.
@param {Event} event
@private