The ticket covers the block manager API testing. To test the block manager API level, we will be utilisng the unit testing framework and directly calling the API calls with expectations set. This ticket is to aim to unit test the relevant open and close APIs used for the block manager module. This ticket will create API tests for:

• bm->addr_string
• bm->block_header
• bm->is_mapped
• bm->size
• bm->stat

The definition of done, will be thoroughly API misc functions