PsiStatic (static_val)
When PsiStatic is applied to a distribution or a time series, the passed static value is returned when a simulation has not yet been performed.
Example:
- PsiBernoulli(0.7) will return the value, 0.7, before a simulation is performed.
- PsiBernoulli(0.7, PsiStatic(1)) will return a 1, before a simulation is performed.