@Override
  public int findScalarInMap(MapColumnVector mapColumnVector, int mapBatchIndex) {
    final int offset = (int) mapColumnVector.offsets[mapBatchIndex];
    final int count = (int) mapColumnVector.lengths[mapBatchIndex];
    double[] keys = ((DoubleColumnVector) mapColumnVector.keys).vector;
    for (int i = 0; i < count; i++) {
      if (key == keys[offset + i]) {
        return offset + i;
      }
    }
    return -1;
  }
Returns value of Map.
Extends {@link VectorUDFMapIndexBaseScalar}
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/VectorUDFMapIndexDoubleScalar.java