In the source for the `expr` command, LLDB sets the `SetKeepInMemory` flag on ExpressionOptions which allows something like: ``` (lldb) expr -l ObjC -- int (^$double)(int) = ^int(int num) { return num*2; }; (lldb) expr -l ObjC -- $double(2); (int) $1 = 4 ``` However, doing the same via the Python API is not possible, there is no switch on SBExpressionOptions to keep a variable saved for future expressions.