How to limit the display area of leaflet, ask for an example

how to set leaflet to limit the display area, and automatically bounce back when it is out of range. After reading the official document, you just don"t know how to use it

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Mar.04,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e49a2f-44d46.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e49a2f-44d46.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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