loadOtherHalfAcrossChunkBorder

Paper only pairs two chest halves while both of their chunks are loaded, so a double chest that sits across a chunk border reads as a single 27-slot chest when only this half's chunk is loaded. That is the usual state when the owner dies far away. For a chest on a chunk edge that does not currently pair, this loads the chunk holding the other half named by the block data, once and without a plugin chunk ticket or force-loading, so the next getState() returns the whole double chest. Every other chest is left as it is.