a block does not shrink itself (for now)
add some assertions
REF merging blocks in put
do not attempt to shrink blocks of lvl 0
fix: we may have two consecutive dead blocks of same level
works for 1 thread
add some assertions
fix: maintain last block
fix an issue with move
TODO
remove dead code
try_shrink returns true if block was shrunk
REF
add assertion
fix: avoid non-termination after moving a block
rename method
removed some debug code
DOC