This update brings a bunch of improvements to the InvseeAPI.
First of all, the Api is now documented on the wiki on GitHub!

The following changes were made to the Api:

• Optimised SpectatorInventory cache - no longer iterates over all online players.
• Properly implemented methods in MainSpectatorInventory for checking whether items exist, or removing items from the inventory. (Adding items was already properly implemented.)
  • This fixes a bug in InvSee++_Clear where items wouldn't be removed from the armour slots, cursor slot, offhand slot, or personal slots.
• Added PlayerInventorySlot#defaultIndex, PlayerInventorySlot#byDefaultIndex, EnderChestSlot#defaultIndex, EnderChestSlot#byDefaultIndex.
• Addressed a code smell where a mutable public field was used to set the bukkit wrapper for nms inventories.
• Default values for customisation parameters (Title, OfflineSupport, Mirror) are now obtained from InvSee++'s config.

Other changes:

• Fixed an issue where tabcompletion on Paper API-enabled servers would not work as intended (the first character was case-insensitive, but the others were not).
• Dropped support for CraftBukkit 1.19. (1.19.2 and 1.19.3 are still supported)
• Fixed an issue in the PerWorldInventory integration caused by not doing world-specific permission checks.
• The project is now licensed under the LGPLv2.1 since version 0.15.4.

And that brings me to another point. I provide InvSee++ for free, and in most cases I do provide support free of charge as well. While supporting the project financially is completely optional, I would like to remind people that the option to donate exists.

Cheers!