java.lang.NullPointerException: Cannot invoke "java.util.List.iterator()" because "lc" is null at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareDiffChildren(StructureDefinitionComparer.java:553) at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareDiff(StructureDefinitionComparer.java:475) at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareDiffChildren(StructureDefinitionComparer.java:581) at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareDiff(StructureDefinitionComparer.java:475) at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compare(StructureDefinitionComparer.java:179) at org.hl7.fhir.r5.comparison.ComparisonSession.compare(ComparisonSession.java:107) at org.hl7.fhir.igtools.publisher.comparators.IpaComparator.finishChecks(IpaComparator.java:232) at org.hl7.fhir.igtools.publisher.Publisher.checkConformanceResources(Publisher.java:6588) at org.hl7.fhir.igtools.publisher.Publisher.loadConformance2(Publisher.java:6392) at org.hl7.fhir.igtools.publisher.Publisher.createIg(Publisher.java:1208) at org.hl7.fhir.igtools.publisher.Publisher.execute(Publisher.java:1067) at org.hl7.fhir.igtools.publisher.Publisher.main(Publisher.java:15593)