typeKey() {
	        const type_index = this.typeIndex();
	        const stack = this.lib.getOrAllocCallStack();
	        const outOffset = stack.allocPtrArray(1);
	        const outPtr = stack.ptrFromOffset(outOffset);
	        this.lib.checkCall(this.lib.exports.TVMObjectTypeIndex2Key(type_index, outPtr));
	        const result = this.lib.memory.loadCString(this.lib.memory.loadPointer(outPtr));
	        this.lib.recycleCallStack(stack);
	        return result;
	    }
get the type key of the object