@Test public void testJoinKeyNestedTuplesWithCustom() { final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment(); DataSet<Tuple5<CustomType, Long, String, Long, Integer>> ds1 = env.fromCollection(emptyNestedCustomTupleData, nestedCustomTupleTypeInfo); DataSet<Tuple5<Integer, Long, String, Long, Integer>> ds2 = env.fromCollection(emptyTupleData, tupleTypeInfo); try { TypeInformation<?> t = ds1.join(ds2).where("f0.myInt").equalTo(4).getType(); assertTrue("not a composite type", t instanceof CompositeType); } catch (Exception e) { e.printStackTrace(); Assert.fail(); } }