public RequestContextExporterBuilder keyPattern(String keyPattern) {
        requireNonNull(keyPattern, "keyPattern");
        checkArgument(!keyPattern.isEmpty(), "keyPattern must not be empty");
        defaultExportGroupBuilder.keyPattern(keyPattern);
        return this;
    }
Adds the property represented by the specified key pattern to the export list. Please refer to the
<a href="https://armeria.dev/docs/advanced-logging">Logging contextual information</a>
in order to learn how to specify a key pattern.
core/src/main/java/com/linecorp/armeria/common/logging/RequestContextExporterBuilder.java