Index: node_modules/d3-shape/src/curve/bundle.js
===================================================================
--- node_modules/d3-shape/src/curve/bundle.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/bundle.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,56 @@
+import {Basis} from "./basis.js";
+
+function Bundle(context, beta) {
+  this._basis = new Basis(context);
+  this._beta = beta;
+}
+
+Bundle.prototype = {
+  lineStart: function() {
+    this._x = [];
+    this._y = [];
+    this._basis.lineStart();
+  },
+  lineEnd: function() {
+    var x = this._x,
+        y = this._y,
+        j = x.length - 1;
+
+    if (j > 0) {
+      var x0 = x[0],
+          y0 = y[0],
+          dx = x[j] - x0,
+          dy = y[j] - y0,
+          i = -1,
+          t;
+
+      while (++i <= j) {
+        t = i / j;
+        this._basis.point(
+          this._beta * x[i] + (1 - this._beta) * (x0 + t * dx),
+          this._beta * y[i] + (1 - this._beta) * (y0 + t * dy)
+        );
+      }
+    }
+
+    this._x = this._y = null;
+    this._basis.lineEnd();
+  },
+  point: function(x, y) {
+    this._x.push(+x);
+    this._y.push(+y);
+  }
+};
+
+export default (function custom(beta) {
+
+  function bundle(context) {
+    return beta === 1 ? new Basis(context) : new Bundle(context, beta);
+  }
+
+  bundle.beta = function(beta) {
+    return custom(+beta);
+  };
+
+  return bundle;
+})(0.85);
