hover = {
const svg = d3.create('svg')
.attr('width', 300)
.attr('height', 300)
const data = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ].map(() => [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ])
svg.selectAll('g')
.data(data)
.join('g')
.attr('transform', (d,i) => `translate(0,${30 * i})`)
.selectAll('rect')
.data(d => d)
.join('rect')
.attr('x', (d,i) => 30 * i)
.attr('height', 30)
.attr('width', 30)
.style('fill', '#4dbeff')
.on('mouseover', function(e, d) {
d3.select(this)
.transition()
.duration(100)
.style('fill', 'white')
})
.on('mouseout', function(e, d) {
d3.select(this)
.transition()
.duration(2000)
.style('fill', '#4dbeff')
})
return svg.node()
}