formula.wbm: Retrieve model formulas from 'wbm' objects
In panelr: Regression Models and Utilities for Repeated Measures and Panel Data

This S3 method allows you to retrieve the formula used to fit wbm objects.

1 2	## S3 method for class 'wbm' formula(x, raw = FALSE, ...)

`x`	R object, for `DF2formula()` a `data.frame`.
`raw`	Return the formula used in the call to `lmerMod`/`glmerMod`? Default is FALSE.
`...`	further arguments passed to or from other methods.

data("WageData")
wages <- panel_data(WageData, id = id, wave = t)
model <- wbm(lwage ~ lag(union) + wks, data = wages)
# Returns the original model formula rather than the one sent to lme4
formula(model)