Each agent contains a Bag called population. Within population there are
number of IntBags. So population looks like this:
On each step I perform some operations with population, but it is
irrelevant at the moment.

Each 10th(for example) step I want my agents to exchange IntBags(aka
individuals). The problem is that while I can call
map.getNeighborsExactlyWithinDistance() or something similar, and get
individuals from the *copy*(or copies) of neighboring agents method returns
by calling getMigrants() method I created for agent, I can't figure out a
way to remove individuals who migrated from the original neighbor.