import “selection”;
d3_selectionPrototype.transition = function() {
var id = d3_transitionInheritId || ++d3_transitionId, subgroups = [], subgroup, node, transition = d3_transitionInherit || {time: Date.now(), ease: d3_ease_cubicInOut, delay: 0, duration: 250}; for (var j = -1, m = this.length; ++j < m;) { subgroups.push(subgroup = []); for (var group = this[j], i = -1, n = group.length; ++i < n;) { if (node = group[i]) d3_transitionNode(node, i, id, transition); subgroup.push(node); } } return d3_transition(subgroups, id);
};