public static Builder newIntegerColumnDefBuilder() {
    return new Builder();
  }
@Test
  public void builder_setNullable_sets_nullable_field_of_IntegerColumnDef() {
    assertThat(newIntegerColumnDefBuilder().setColumnName("a").setIsNullable(true).build().isNullable()).isTrue();
    assertThat(newIntegerColumnDefBuilder().setColumnName("a").setIsNullable(false).build().isNullable()).isFalse();
  }