Error: iterations has no rows. x must have existing rows so that values of the columns
in by can be used for the merge.

test_that("addResVar works with SIGMA parameters - proportional error only", {
cat("ITERATION THETA1 SIGMA(1,1) SIGMA(2,1) SIGMA(2,2)\n
## write.table(ext_content, temp_ext, row.names = FALSE, quote = FALSE)
# Check that IPREDVAR column was created
# Check that all rows have IPREDVAR values
# Check that IPREDVAR is different from IPRED (due to error)

"addResVar works with SIGMA parameters - proportional error only"

addResVar works with SIGMA parameters - proportional error only