function testKeyOfIndex_NullableKey() {
  var table = order.db.getSchema().getNullableTable();
  var row = table.createRow();
  table.getIndices().forEach(function(indexSchema) {
    assertNull(row.keyOfIndex(indexSchema.getNormalizedName()));
  });
}
Tests that keyOfIndex() is correctly handling nullable fields for a
statically generated schema.