public void setPrefix(String prefix) {
        requireNonNull(prefix, "prefix");
        checkArgument(!prefix.isEmpty(), "prefix must not be empty");
        builder.prefix(prefix);
    }
Specifies a prefix of the default export group.
Note: this method is meant to be used for XML configuration.
logback/logback12/src/main/java/com/linecorp/armeria/common/logback/ExportGroupConfig.java