LogicalExpressionPlan bprojplan = new LogicalExpressionPlan();
ProjectExpression y = new ProjectExpression(bprojplan, 1, 0, C);
y.neverUseForRealSetFieldSchema(new LogicalFieldSchema(null, null, DataType.BYTEARRAY));
mm.put(0, aprojplan);
mm.put(1, bprojplan);
C.neverUseForRealSetSchema(cschema);
expected.add(C);
expected.connect(foreachA, C);
expected.connect(foreachB, C);
// D = filter