    java.lang.OutOfMemoryError: Java heap space
    	at java.base/jdk.internal.misc.Unsafe.allocateUninitializedArray(Unsafe.java:1375)
    	at java.base/java.lang.StringConcatHelper.newArray(StringConcatHelper.java:497)
    	at java.base/java.lang.invoke.DirectMethodHandle$Holder.invokeStatic(DirectMethodHandle$Holder)
    	at java.base/java.lang.invoke.LambdaForm$MH/0x0000004001016400.invoke(LambdaForm$MH)
    	at java.base/java.lang.invoke.Invokers$Holder.linkToTargetMethod(Invokers$Holder)
    	at org.hl7.fhir.r5.utils.DefinitionNavigator.loadChildren(DefinitionNavigator.java:201)
    	at org.hl7.fhir.r5.utils.DefinitionNavigator.children(DefinitionNavigator.java:170)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:363)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareElements(StructureDefinitionComparer.java:295)
    	at org.hl7.fhir.r5.comparison.StructureDefinitionComparer.compareChildren(StructureDefinitionComparer.java:382)