Serial filter(...) expr: all filters but the first are missing in the generated code

[maxkratz]

In some cases, serial filter(...) expressions break the filter semantics.
Example: Echtzeitsysteme/gips-tests#31

constraint -> global {
	mappings.n2n
	->filter(m | m.nodes().vnode.resourceDemand == 0)
	->filter(m | m.nodes().snode.resourceAmountTotal == 0)
	->count() == 0
}

Problem (if I understand it correctly):
If the first filter expression (in this case ->filter(m | m.nodes().vnode.resourceDemand == 0)) filters nothing out, i.e., the result should not be an empty set, the second filter(...) operation could not be triggered and, therefore, the count() does not evaluate to 0?

[maxkratz]

Update: If I understand it correctly, the second filter expression is simply missing in the generated Java code. The expression above compiles to:

[...]
	protected void builder_0(final List<ILPTerm> terms) {
		for(N2nMapping itr_0 : engine.getMapper("n2n").getMappings().values().parallelStream()
			.map(mapping -> (N2nMapping) mapping)
			.filter(itr_0 -> itr_0.getVnode().getResourceDemand() == 0).collect(Collectors.toList())) {
			terms.add(new ILPTerm(itr_0, (double)1.0));
				}
	}
[...]