public Map<String, AttributeKey<?>> attributes() {
        if (attrs == null) {
            return ImmutableMap.of();
        }
        return Arrays.stream(attrs).collect(toImmutableMap(e -> e.exportKey, e -> e.key));
    }
Returns all {@link AttributeKey}s in the export list.

@return the {@link Map} whose key is an alias and value is an {@link AttributeKey}
core/src/main/java/com/linecorp/armeria/common/logging/RequestContextExporter.java