Model
MergePlugin
Magento\PageCache\Model\Layout\MergePlugin
What it does
This plugin prevents ESI (Edge Side Include) blocks from being declared in entity-specific layout handles (like product or category pages with IDs).
It validates layout XML updates before they're processed and throws an error if a handle contains TTL attributes, which would cause caching issues since entity-specific blocks can't be shared between different pages.
Public Methods
- beforeValidateUpdate()