During 0-1
   Task 1 completes its first initiate
   Task 2 completes its first initiate

During 1-2
   Task 1 completes its second initiate
   Task 2 completes its second initiate

During 2-3
   Task 1 completes its request
   Task 2's request cannot be granted (not safe).  So 2 is blocked.
Avail = 1,2 (1 unit of 1, 2 units of 2) at 3

During 3-4
   Banker first checks blocked tasks but cannot grant 2's request (not safe).
   Task 1 completes its request
Avail = 0,2 at 4

During 4-5
   Banker first checks blocked tasks but cannot grant 2's request (not safe).
   Task 1 completes its request
Avail = 0,1 at 5

During 5-6
   Banker first checks blocked tasks but cannot grant 2's request (not safe).
   Task 1 releases two units (available at 6)
Avail = 2,1 at 6

During 6-7
   Banker first checks blocked tasks but cannot grant 2's request (not safe).
   Task 1 releases one unit (available at 7) and terminates at 7
Avail = 2,2 at 7

During 7-8
   Banker first checks blocked tasks and can grant 2's request.
Avail = 1,2 at 8

During 8-9
   Task 2 completes its request
Avail = 0,2 at 9

During 9-10
   Task 2 completes its request
Avail = 0,1 at 10

During 10-11
   Task 2 releases 2 units (available at 11)
Avail = 2,1 at 11

During 11-12
   Task 2 releases 1 unit (available at 12) and terminates at 12
Avail = 2,2 at 12