The imaginal system is used to store intermediate problem state representations. Typically used in conjunction with the goal module which retains the goal state.
The imaginal system is time dependent (unlike the goal module), so all imaginal buffer operations take some (configurable) amount of time.
DefaultImaginalModule6 is the default implementation of the imaginal system.
It provides the imaginal buffer, and has parameters to manipulate the amount of time add and modify requests take.