Masterpress 1.3.6 is a compatibility release. It resolves an edge case with shared fieldsets not working for MySQL 8 when the fieldset is limited to more than 1 post type or taxonomy or excluding any post types or taxonomies.
WOOF_Collection :: index_of( Mixed $value, String $prop = "id" )
- Integer The index of the item in the collection, if found, or -1 otherwise
Returns the index of the given item, searching each object in the collection for a given value from the specified property