Circle = {
  init: function(svg, values, cxAccessor, cyAccessor){
    return svg.selectAll("circle")
        .data(values)
        .enter()
          .append("circle")
            .attr("cx", cxAccessor)
            .attr("cy", cyAccessor)
            .attr("r", "5px")
            .style("fill", "pink")
            .attr("stroke", "blue")
            .attr("stroke-width", "2px");
  }
};