public EndpointInfoBuilder regexPathPrefix(String regexPathPrefix) {
        requireNonNull(regexPathPrefix, "regexPathPrefix");
        checkState(fragment == null, "regexPathPrefix cannot be set with fragment: %s", fragment);
        this.regexPathPrefix = regexPathPrefix;
        return this;
    }
Sets the prefix of the pathMapping if the {@code pathMapping} is a regular expression string and
the prefix exists.
core/src/main/java/com/linecorp/armeria/server/docs/EndpointInfoBuilder.java