it is not possible to get current objective bounds between solutions

[gregy4]

What language and solver does this apply to?
Python, Java / CP-SAT

Describe the problem you are trying to solve.
It is not possible to get current objective bounds between solutions. It is only shown in a log.

Describe the solution you'd like
New method in solution callback. Executed when new bound of objective function is found.
or
Update value of best objective bound so it can be read externally. So far it seems it is updated only when a solution is found.

Add relative gap in a log for #bound event, especially for large domains it can be more helpful then numbers:
#4 0.07s best:3.837456e+10 next:[2.18861401e+10,3.83745599e+10] graph_var_lns (d=0.50 s=39 t=0.10 p=0.00 stall=0 h=auto_l0) [hint]

Describe alternatives you've considered
I tried to use external timer but best objective bound isn't updated between solutions.