docs: public Optional<SanitizedContentKind> getCallContentKind(CallNode node) {
      ImmutableList<TemplateMetadata> templateNodes = getTemplates(node);
      // For per-file compilation, we may not have any of the delegate templates in the compilation
      // unit.
      if (!templateNodes.isEmpty()) {
        return Optional.fromNullable(templateNodes.get(0).getContentKind());
      }
      // The template node may be null if the template is being compiled in isolation.
      return Optional.absent();
    }