Check for common errors in specifying id, sex, and race columns for discord regressions.
check_discord_errors(data, id, sex, race, pair_identifiers)
An error message if one of the conditions are met.
The data to perform a discord regression on.
A unique kinship pair identifier.
A character string for the sex column name.
A character string for the race column name.
A character vector of length two that contains the variable identifier for each kinship pair.