feature: vor und nachteile

praesentation/node_modules/d3-selection/src/array.js

@@ -0,0 +1,9 @@
+// Given something array like (or null), returns something that is strictly an
+// array. This is used to ensure that array-like objects passed to d3.selectAll
+// or selection.selectAll are converted into proper arrays when creating a
+// selection; we don’t ever want to create a selection backed by a live
+// HTMLCollection or NodeList. However, note that selection.selectAll will use a
+// static NodeList as a group, since it safely derived from querySelectorAll.
+export default function array(x) {
+  return x == null ? [] : Array.isArray(x) ? x : Array.from(x);
+}