simulate.tergm() for CMLE/CMPLE should provide a way to simulate each network conditional on prior network.

[krivit]

Right now, simulate.tergm() always attempts to run the temporal process forward. However, for GOF and other purposes, we may want to simulate what the networks in the time series "could have been" conditional on their respective previous time steps.

Since tergm_CMLE directly inherits from ergm, we should just be able to pass it through to simulate.ergm() if, say, dynamic=FALSE.