code: final PropertyAccessKind getPropertyAccessKind(String property) {
      return getExternGetterAndSetterProperties()
          .getOrDefault(property, PropertyAccessKind.NORMAL)
          .unionWith(
              getSourceGetterAndSetterProperties().getOrDefault(property, PropertyAccessKind.NORMAL));
    }
docs: Returns any property seen in the externs or source with the given name was a getter, setter, or
  both.
  
  <p>This defaults to {@link PropertyAccessKind#NORMAL} for any property not known to have a
  getter or setter, even for property names that do not exist in the given program.