---@field get_float fun(self: MetaDataRef, key): integer|number Returns `0` if key not present.
---@field to_table fun(): nil Returns `nil` or a table with keys: `fields`: key-value storage `inventory`: `{list1 = {}, ...}}` (NodeMetaRef only)
---@field from_table fun(self: MetaDataRef, t: nil|table): boolean Any non-table value will clear the metadata. Returns `true` on success
---@field equals fun(self: MetaDataRef, other: any): boolean Returns `true` if this metadata has the same key-value pairs as `other`
---ItemStack metadata: reference extra data and functionality stored in a stack. Can be obtained via `item:get_meta()`.
---@class ItemStackMetaRefAbstract
---@field set_tool_capabilities fun(self: ItemStackMetaRef, tool_capabilities?: table): nil Overrides the item's tool capabilities. A nil value will clear the override data and restore the original behavior.
---Node metadata: reference extra data and functionality stored in a node. Can be obtained via `minetest.get_meta(pos)`.
---@field mark_as_private fun(self: NodeMetaRef, name: string | table<string[]>) Mark specific vars as private This will prevent them from being sent to the client. Note that the "private" status will only be remembered if an associated key-value pair exists, meaning it's best to call this when initializing all other meta (e.g. `on_construct`).
---Player metadata. Uses the same method of storage as the deprecated player attribute API, so data there will also be in player meta. Can be obtained using `player:get_meta()`.
---@class PlayerMetaRefAbstract
---Mod metadata: per mod metadata, saved automatically. Can be obtained via `minetest.get_mod_storage()` during load time. WARNING: This storage backend is incapable of saving raw binary data due to restrictions of JSON.