packages/perspective-viewer-highcharts/src/js/highcharts/externals.js
function walk(arr, key, fn) {
        var l = arr.length,
            children;

        while (l--) {
            children = arr[l][key];

            if (children) {
                walk(children, key, fn);
            }
            fn(arr[l]);
        }
    }
function walk(arr, key, fn) {
        var l = arr.length,
            children;

        while (l--) {
            children = arr[l][key];

            if (children) {
                walk(children, key, fn);
            }
            fn(arr[l]);
        }
    }
function walk ( arr , key , fn ) { var l = arr . length , children ; while ( l -- ) { children = arr [ l ] [ key ] ; if ( children ) { walk ( children , key , fn ) ; } fn ( arr [ l ] ) ; } }
Pushes part of grid to path
Pushes part of grid to path