function buildPath(lines, jumpSize, jumpType) {
        // first move to the start of a first line
        var start = ['M', lines[0].start.x, lines[0].start.y];

        // make a paths from lines
        var paths = _(lines).map(function(line) {
            if (line.isJump) {
                if (jumpType === 'arc') {
                    var diff = line.start.difference(line.end);
                    // determine rotation of arc based on difference between points
                    var xAxisRotate = Number(diff.x < 0 && diff.y < 0);
                    // for a jump line we create a arc instead
                    return ['A', jumpSize, jumpSize, 0, 0, xAxisRotate, line.end.x, line.end.y];
                } else if (jumpType === 'gap') {
                    return ['M', line.end.x, line.end.y];
                }
            }
            return ['L', line.end.x, line.end.y];
        }).flatten().value();

        return [].concat(start, paths).join(' ');
    }
Assemble `D` attribute of a SVG path by iterating given lines.
@param {g.line[]} lines source lines to use
@param {number} jumpSize the size of jump arc (length empty spot on a line)
@return {string}