remove useless check

Author: KSDaemon

packages/cubejs-schema-compiler/src/compiler/CubeEvaluator.ts

@@ -256,25 +256,17 @@ export class CubeEvaluator extends CubeSymbols {
   }
 
   private prepareHierarchies(cube: any, errorReporter: ErrorReporter): void {
-    const uniqueHierarchyNames = new Set();
     if (Object.keys(cube.hierarchies).length) {
-      cube.evaluatedHierarchies = Object.entries(cube.hierarchies).map(([name, hierarchy]) => {
-        if (uniqueHierarchyNames.has(name)) {
-          errorReporter.error(`Duplicate hierarchy name '${name}' in cube '${cube.name}'`);
-        }
-        uniqueHierarchyNames.add(name);
-
-        return ({
-          name,
-          ...(typeof hierarchy === 'object' ? hierarchy : {}),
-          levels: this.evaluateReferences(
-            cube.name,
-            // @ts-ignore
-            hierarchy.levels,
-            { originalSorting: true }
-          )
-        });
-      });
+      cube.evaluatedHierarchies = Object.entries(cube.hierarchies).map(([name, hierarchy]) => ({
+        name,
+        ...(typeof hierarchy === 'object' ? hierarchy : {}),
+        levels: this.evaluateReferences(
+          cube.name,
+          // @ts-ignore
+          hierarchy.levels,
+          { originalSorting: true }
+        )
+      }));
     }
 
     if (cube.isView && (cube.includedMembers || []).length) {