{
function handleMouseOver(d, i) {
d3.select(this)
.attr("fill", "pink")};
function handleMouseOut(d, i) {
d3.select(this).attr("fill", "steelblue")};
let svg = d3.select(DOM.svg(width, height));
let g = svg.append( "g" );
let rodents = svg.append( "g" );
g.selectAll( "path" )
.data( bosNeighborhoods.features )
.enter()
.append( "path" )
.attr( "fill", "#ccc" )
.attr( "stroke", "#333")
.attr( "d", bos_geoPath );
rodents.selectAll( "path" )
.data( rodentData.features )
.enter()
.append( "path" )
.attr( "fill", "steelblue" )
.attr( "stroke", "none" )
.attr( "opacity", 0.5)
.attr( "d", bos_geoPath )
.attr("class", "incident")
.on("click", d => d3.select("#label").text(d.properties.LOCATION_STREET_NAME))
.on("mouseover", handleMouseOver)
.on("mouseout", handleMouseOut);
return svg.node();
}