private void assertMapType(OpenType<?> mapType, OpenType<?> keyType, OpenType<?> valueType) {
   TabularType type = assertCast(TabularType.class, mapType);
   Assert.assertEquals(1, type.getIndexNames().size());
   Assert.assertEquals("key", type.getIndexNames().get(0));
   Assert.assertEquals(2, type.getRowType().keySet().size());
   Assert.assertTrue(type.getRowType().keySet().contains("key"));
   Assert.assertTrue(type.getRowType().keySet().contains("value"));
   Assert.assertEquals(keyType, type.getRowType().getType("key"));
   Assert.assertEquals(valueType, type.getRowType().getType("value"));
 }