TreeMap specific override of putIfAbsent/merge

[Tomasz Kowalczewski]

Hi all,

TreeMap does not have its own specific overrides of Map methods that were
added in java 8. In our specific usage we do what is effective a merge
operation:

For incoming K and V:
1. get value from map
2. if present - merge with incoming value V
3. if absent - associate K with V in the map

For case where K is not in the map we traverse the tree map it twice.
Implementing TreeMap specific override of putIfAbsent would allow as to
avoid this cost.

Was such change considered in past and rejected? Is anyone interested in a
patch that implements it?

-- 
Regards,
Tomasz Kowalczewski