public ExceptionInfo withFields(Iterable<FieldInfo> fields) {
        requireNonNull(fields, "fields");
        if (fields.equals(this.fields)) {
            return this;
        }

        return new ExceptionInfo(name, fields, descriptionInfo);
    }
Returns a new {@link ExceptionInfo} with the specified {@link FieldInfo}s.
Returns {@code this} if this {@link ExceptionInfo} has the same {@link FieldInfo}s.
core/src/main/java/com/linecorp/armeria/server/docs/ExceptionInfo.java