private Constructor<?> getConstructor(Class<?> cl) throws HiveException {
    try {
      Constructor<?> [] ctors = cl.getDeclaredConstructors();
      if (ctors.length == 1) {
        return ctors[0];
      }
      Constructor<?> defaultCtor = cl.getConstructor();
      for (Constructor<?> ctor : ctors) {
        if (!ctor.equals(defaultCtor)) {
          return ctor;
        }
      }
      throw new HiveException("Only default constructor found");
    } catch (Exception ex) {
      throw new HiveException(ex);
    }
  }
Invoke special handling for expressions that can't be vectorized by regular
descriptor based lookup.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorizationContext.java