add func renderHeaderColumn

package.json

@@ -86,5 +86,15 @@
   },
   "resolutions": {
     "graceful-fs": "^4.2.4"
+  },
+  "babel": {
+    "presets": [
+      "@babel/preset-react",
+      "@babel/preset-env"
+    ],
+    "plugins": [
+      "@babel/plugin-transform-react-jsx",
+      "@babel/plugin-proposal-class-properties"
+    ]
   }
 }

src/ReactFinder.js

@@ -122,18 +122,22 @@ class ReactFinder extends PureComponent {
     }
 
     renderDetail() {
-        const {renderDetail, dataSource, nodeKey, childrenPropName} = this.props;
-        const {selectedKey} = this.state;
+        const { renderDetail, dataSource, nodeKey, childrenPropName } = this.props;
+        const { selectedKey } = this.state;
 
         const el = renderDetail && renderDetail({
             selectedKey,
             selectedData: findInTree(
                 dataSource,
-                n => n[nodeKey] === selectedKey, {childrenName: childrenPropName}
+                n => n[nodeKey] === selectedKey, { childrenName: childrenPropName }
             )
         });
         if (el) {
-            return (<div className="react-finder-detail">{el}</div>);
+            return (
+                <div className="react-finder-detail">
+                    {el}
+                </div>
+            );
         }
         return null;
     }