Index: node_modules/recharts/es6/zIndex/getZIndexFromUnknown.js
===================================================================
--- node_modules/recharts/es6/zIndex/getZIndexFromUnknown.js	(revision a762898ecd37a452c782821d4c2c4955c6ed2521)
+++ node_modules/recharts/es6/zIndex/getZIndexFromUnknown.js	(revision a762898ecd37a452c782821d4c2c4955c6ed2521)
@@ -0,0 +1,7 @@
+import { isWellBehavedNumber } from '../util/isWellBehavedNumber';
+export function getZIndexFromUnknown(input, defaultZIndex) {
+  if (input && typeof input === 'object' && 'zIndex' in input && typeof input.zIndex === 'number' && isWellBehavedNumber(input.zIndex)) {
+    return input.zIndex;
+  }
+  return defaultZIndex;
+}