Update lib/src/commands/LayoutTreeParser.ts

Author: jpdriver

lib/src/commands/LayoutTreeParser.ts

@@ -140,7 +140,7 @@ export class LayoutTreeParser {
     } else {
       // api is ModernLayoutSplitView
       const primary = this.parse(api.primary);
-      const supplementary = api.supplementary ? this.parse(api.secondary) : undefined;
+      const supplementary = api.supplementary ? this.parse(api.supplementary) : undefined;
       const secondary = this.parse(api.secondary);
 
       return {