## Notes
json! macro can panic, should probably not be used in library code
Questionnaire.item.item -> repeater map for types
Observation.component.value.value -> type mapping
is / as should also check if the type is a sub type
Quantity equality
Quantity conversion
Equality/Equivalent for complex objects -> respect Quantity conversion?
Resource.contained -> reset path to contained resource
Bundle.entry.resource -> correct type?
children() and descendants() - we currently return any nodes that are children/descendants, which seems to differ
with other implementations, there is discussion here https://chat.fhir.org/#narrow/channel/179298-fhirpath.2Ejs/topic/descendants.28.29
on the correct way to do this. This implementation also doesn't flatten array nodes out, which all other implementations appear to do.
Time equality does not respect second / millisecond comparison