text: import { select } from "d3-selection"
  
  const space = '&nbsp;'
  const line = '—————————————'
  const block = '<span class="block"></span>'
  
  
  export function mouseover(node) {
  
      const focus = select('body').append('div').attr('id', 'focus')
  
      // Heading
  
      focus.append('h2').html(node.name)
      focus.append('h2').html(`${node.affiliation}`)
      focus.append('h2').html(`${node.docs} Publications`)
  
      // Tokens
  
      focus.append('p').html(space)
      focus.append('h3').html('Tokens by tf-idf')
      focus.append('p').html(line)
      Object.entries(node.tokens).slice(0, 20)
          .forEach(([key, value]) => {
              const blocks = block.repeat(value)
              focus.append('p').html(`${blocks} &nbsp; ${key}`)
          })
  
      // Years
  
      focus.append('p').html(space)
      focus.append('h3').html('Publication Years')
      focus.append('p').html(line)
  
      Object.entries(node.years).forEach(([key, value], i) => {
          const blocks = block.repeat(value * 4)
          focus.append('p').html(`${blocks} &nbsp; ${key}`)
      })
  
  }
  
  export function mouseout() {
  
      select('#focus').remove()
      s.tokens = []
  
  }