code: def get_nbt(self,x,z):
          
          rx,cx = divmod(x,32)
          rz,cz = divmod(z,32)
          if (rx,rz) not in self.regions and (rx,rz) not in self.regionfiles:
              raise InconceivedChunk("Chunk %s,%s is not present in world" % (x,z))
          nbt = self.get_region(rx,rz).get_nbt(cx,cz)
          assert nbt != None
          return nbt
docs: Return a NBT specified by the chunk coordinates x,z. Raise InconceivedChunk
          if the NBT file is not yet generated. To get a Chunk object, use get_chunk.