//0x58 bytes (sizeof)
struct _IO_WORKITEM
{
    struct _WORK_QUEUE_ITEM WorkItem;                                       //0x0
    VOID (*Routine)(VOID* arg1, VOID* arg2, struct _IO_WORKITEM* arg3);     //0x20
    VOID* IoObject;                                                         //0x28
    VOID* Context;                                                          //0x30
    struct _ETHREAD* WorkOnBehalfThread;                                    //0x38
    ULONG Type;                                                             //0x40
    struct _GUID ActivityId;                                                //0x44
};