    pushState()
      restartSimulation()
    })

  d3.select('#chronology')
    .on('change', event => {
      chronology = event.srcElement.checked
      pushState()
      restartSimulation()
    })

  let searchResult = []
  d3.select('#search')
    .on('input', event => {
      const s = event.srcElement.value.trim()
      if (s !== '') {
        const maxSearchResult = 10
        const r = new RegExp(s, 'i')
        let count = 0
        searchResult = nodes.filter(n => (
          r.test(n.id) ||
    