Calls come from ... in simulateTrialData. For individual level data,
empirical quantile will be generated using simdata::quantile_functions_from_data.
For calls specifying common distribution families and their parameters in plain text,
quantile functions will be generated by quantile functions in stats, e.g.,
qnorm, qunif, etc. For calls of user-customized quantile functions, it returns
those directly.
configureTrial(..., var_prefix)a list of quantile functions.
calls describing the marginal distributions of endpoints. See ...
in simulateTrialData.
prefix to name variables that users do not give to those.