`xl.meta` is a new self describing backend format used by MinIO to support AWS S3 compatible versioning.
This file is the source of truth for each `version` at rest. `xl.meta` is a msgpack file serialized from a
well defined data structure. To understand `xl.meta` here are the few things to start with

`xl.meta` carries first 8 bytes an XL header which describes the current format and the format version,

({name:"birthdate",validatorFunction:function(c,d,e){var f="yyyy-mm-dd";d.valAttr("format")?f=d.valAttr("format"):"undefined"!=typeof e.dateFormat&&(f=e.dateFormat);var g=a.formUtils.parseDate(c,f);if(!g)return!1;var h=g[0],i=g[1],j=g[2],k=b(h,i,j),l=(d.valAttr("age-range")||"0-124").split("-");if(d.trigger("ageCalculated",[k]),2!==l.length||!a.isNumeric(l[0])||!a.isNumeric(l[1]))throw new Error("Date range format invalid");return k>=l[0]&&k<=l[1]},errorMessage:"",errorMessageKey:"badDate"})}(a)});...

                    type: integer
                    format: int64
                    example: 0
                  page_size:
                    type: integer
                    example: 20
                  page_number:
                    type: integer
                    example: 1
                  record_count:
                    type: integer
                    format: int64
                    example: 31625

     * @see String#format(String, Object...)
     *
     * @param pattern a <a href="../util/Formatter.html#syntax">format string</a>
     * @param args arguments referenced by the format specifiers in the format string
     * @return the current builder
     */
    @Nonnull
    default MessageBuilder format(String pattern, Object... args) {
        return append(String.format(pattern, args));
    }

    /**

            parent.appendChild(caution);
            Element para = document.createElement("para");
            caution.appendChild(para);
            para.appendChild(document.createTextNode(String.format("Note: This %s is ", type)));
            Element link = document.createElement("ulink");
            para.appendChild(link);
            link.setAttribute("url", "../userguide/feature_lifecycle.html");

    val direction = if (inbound) "<<" else ">>"
    return format(
      "%s 0x%08x %5d %-13s %d",
      direction,
      streamId,
      length,
      formattedType,
      windowSizeIncrement,
    )
  }

  internal fun formattedType(type: Int): String = if (type < FRAME_NAMES.size) FRAME_NAMES[type] else format("0x%02x", type)

  /**

    public LinkMetaData getMethod(String method) {
        MethodLinkMetaData methodMetaData = findMethod(method);
        String urlFragment = methodMetaData.getUrlFragment(className);
        String displayName = String.format("%s.%s", simpleName, methodMetaData.getDisplayName());
        return new LinkMetaData(methodMetaData.style, displayName, urlFragment);
    }

    private MethodLinkMetaData findMethod(String method) {

 */
package org.codelibs.fess.es.log.exbhv;

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.regex.Pattern;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.es.log.bsbhv.BsFavoriteLogBhv;

 */
package org.codelibs.fess.es.log.exbhv;

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.regex.Pattern;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.es.log.bsbhv.BsUserInfoBhv;

        "type": "keyword"
      },
      "order": {
        "type": "integer"
      },
      "requestedAt": {
        "type": "date",
        "format": "date_optional_time"
      },
      "queryRequestedAt": {
        "type": "date",
        "format": "date_optional_time"
      }
    }