public HeadersSanitizer<JsonNode> build() {
        final ObjectMapper objectMapper = this.objectMapper != null ?
                                          this.objectMapper : JacksonUtil.newDefaultObjectMapper();
        return new JsonHeadersSanitizer(sensitiveHeaders(), maskingFunction(), objectMapper);
    }
Returns a newly created JSON {@link HeadersSanitizer} based on the properties of this builder.
core/src/main/java/com/linecorp/armeria/common/logging/JsonHeadersSanitizerBuilder.java