@Test
  public void testFixedType() {
    // Build a required uint field definition
    MajorType.Builder typeBuilder = MajorType.newBuilder();
    FieldDef.Builder defBuilder = FieldDef.newBuilder();
    typeBuilder.setMinorType(MinorType.UINT4).setMode(DataMode.REQUIRED).setWidth(4);
    defBuilder.setMajorType(typeBuilder.build());
    MaterializedField field = MaterializedField.create(defBuilder.build());

    // Create a new value vector for 1024 integers
    UInt4Vector v = new UInt4Vector(field, allocator);
    UInt4Vector.Mutator m = v.getMutator();
    v.allocateNew(1024);

    // Put and set a few values
    m.set(0, 100);
    m.set(1, 101);
    m.set(100, 102);
    m.set(1022, 103);
    m.set(1023, 104);
    assertEquals(100, v.getAccessor().get(0));
    assertEquals(101, v.getAccessor().get(1));
    assertEquals(102, v.getAccessor().get(100));
    assertEquals(103, v.getAccessor().get(1022));
    assertEquals(104, v.getAccessor().get(1023));

    // Ensure unallocated space returns 0
    assertEquals(0, v.getAccessor().get(3));
  }
 /**
  * Marks all values since the last set as empty. The last set value is obtained from underlying
  * offsets vector.
  *
  * @param lastIndex the last index (inclusive) in the offsets vector until which empty population
  *     takes place
  * @throws java.lang.IndexOutOfBoundsException if lastIndex is negative or greater than offsets
  *     capacity.
  */
 public void populate(int lastIndex) {
   if (lastIndex < 0) {
     throw new IndexOutOfBoundsException("index cannot be negative");
   }
   final UInt4Vector.Accessor accessor = offsets.getAccessor();
   final UInt4Vector.Mutator mutator = offsets.getMutator();
   final int lastSet = Math.max(accessor.getValueCount() - 1, 0);
   final int previousEnd = accessor.get(lastSet); // 0 ? 0 : accessor.get(lastSet);
   for (int i = lastSet; i < lastIndex; i++) {
     mutator.setSafe(i + 1, previousEnd);
   }
   mutator.setValueCount(lastIndex + 1);
 }
  @Test
  public void testFixedType() {
    final MaterializedField field = MaterializedField.create(EMPTY_SCHEMA_PATH, UInt4Holder.TYPE);

    // Create a new value vector for 1024 integers.
    try (final UInt4Vector vector = new UInt4Vector(field, allocator)) {
      final UInt4Vector.Mutator m = vector.getMutator();
      vector.allocateNew(1024);

      // Put and set a few values
      m.setSafe(0, 100);
      m.setSafe(1, 101);
      m.setSafe(100, 102);
      m.setSafe(1022, 103);
      m.setSafe(1023, 104);

      final UInt4Vector.Accessor accessor = vector.getAccessor();
      assertEquals(100, accessor.get(0));
      assertEquals(101, accessor.get(1));
      assertEquals(102, accessor.get(100));
      assertEquals(103, accessor.get(1022));
      assertEquals(104, accessor.get(1023));
    }
  }