Quadruple connections being created on pool when using pool.on('connection') event ?

I copied from the documentation this example: https://mariadb.com/docs/connectors/mariadb-connector-nodejs/connector-nodejs-promise-api#connection my code is as follows: ``` const mariadb = require('mariadb'); const settings = require('../appSettings.json').mariadb; const pool = mariadb.createPool({ ...settings, connectionLimit: 10, maxAllowedPacket: 4 * 1024 * 1024,//4MB permitSetMultiParamEntries: true, bigIntAsNumber: true, decimalAsNumber: true, insertIdAsNumber: true }); pool.on('connection', conn => { console.log(`New connection ${conn.threadId} created in pool`); // You can initialize connections with specific settings conn.query(`SET @k = NULL`); }); ``` I get in the console: ``` New connection 1017 created in pool New connection 1018 created in pool New connection 1019 created in pool New connection 1020 created in pool New connection 1021 created in pool New connection 1022 created in pool New connection 1023 created in pool New connection 1024 created in pool New connection 1025 created in pool New connection 1026 created in pool New connection 1028 created in pool New connection 1027 created in pool New connection 1029 created in pool New connection 1030 created in pool New connection 1031 created in pool New connection 1032 created in pool New connection 1034 created in pool New connection 1033 created in pool New connection 1035 created in pool New connection 1036 created in pool New connection 1037 created in pool New connection 1038 created in pool New connection 1039 created in pool New connection 1040 created in pool New connection 1042 created in pool New connection 1041 created in pool New connection 1043 created in pool New connection 1044 created in pool New connection 1046 created in pool New connection 1045 created in pool New connection 1047 created in pool New connection 1048 created in pool New connection 1049 created in pool New connection 1050 created in pool New connection 1051 created in pool New connection 1052 created in pool New connection 1054 created in pool New connection 1053 created in pool New connection 1055 created in pool New connection 1056 created in pool ``` It's 4 times as much... what's going on?