@SuppressWarnings("unchecked")
 public void insertDoubleTuples(IIndexTestContext ctx, int numTuples, Random rnd)
     throws Exception {
   int fieldCount = ctx.getFieldCount();
   int numKeyFields = ctx.getKeyFieldCount();
   double[] fieldValues = new double[ctx.getFieldCount()];
   // Scale range of values according to number of keys.
   // For example, for 2 keys we want the square root of numTuples, for 3
   // keys the cube root of numTuples, etc.
   double maxValue = Math.ceil(Math.pow(numTuples, 1.0 / (double) numKeyFields));
   for (int i = 0; i < numTuples; i++) {
     // Set keys.
     setDoubleKeyFields(fieldValues, numKeyFields, maxValue, rnd);
     // Set values.
     setDoublePayloadFields(fieldValues, numKeyFields, fieldCount);
     TupleUtils.createDoubleTuple(ctx.getTupleBuilder(), ctx.getTuple(), fieldValues);
     if (LOGGER.isLoggable(Level.INFO)) {
       if ((i + 1) % (numTuples / Math.min(10, numTuples)) == 0) {
         LOGGER.info("Inserting Tuple " + (i + 1) + "/" + numTuples);
       }
     }
     try {
       ctx.getIndexAccessor().insert(ctx.getTuple());
       ctx.insertCheckTuple(
           createDoubleCheckTuple(fieldValues, ctx.getKeyFieldCount()), ctx.getCheckTuples());
     } catch (TreeIndexException e) {
       // We set expected values only after insertion succeeds because
       // we
       // ignore duplicate keys.
     }
   }
 }