[Graph]: reduce overhead of stealing vertices from other threads.
[Graph]: reduce overhead of stealing vertices from other threads.

icoming/FlashGraph,icoming/FlashX,silky/FlashGraph,zheng-da/FlashX,zheng-da/FlashX,flashxio/FlashX,icoming/FlashX,zheng-da/FlashX,icoming/FlashX,flashxio/FlashX,silky/FlashGraph,icoming/FlashGraph,flashxio/FlashX,silky/FlashGraph,icoming/FlashX,icoming/FlashGraph,zheng-da/FlashX,flashxio/FlashX,icoming/FlashGraph,icoming/FlashGraph,flashxio/FlashX,silky/FlashGraph,zheng-da/FlashX,icoming/FlashX,silky/FlashGraph,flashxio/FlashX