Index: node_modules/d3-geo/src/clip/extent.js
===================================================================
--- node_modules/d3-geo/src/clip/extent.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-geo/src/clip/extent.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,20 @@
+import clipRectangle from "./rectangle.js";
+
+export default function() {
+  var x0 = 0,
+      y0 = 0,
+      x1 = 960,
+      y1 = 500,
+      cache,
+      cacheStream,
+      clip;
+
+  return clip = {
+    stream: function(stream) {
+      return cache && cacheStream === stream ? cache : cache = clipRectangle(x0, y0, x1, y1)(cacheStream = stream);
+    },
+    extent: function(_) {
+      return arguments.length ? (x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1], cache = cacheStream = null, clip) : [[x0, y0], [x1, y1]];
+    }
+  };
+}