This allows the suppressMessages to work on print functions. This captures the output function sends it through the message routine.
nlmixrPrint(x, ...)object to print
Other things output
Nothing, called for its side effects
catpureOutput was used since it is much faster than the internal capture.output see https://www.r-bloggers.com/performance-captureoutput-is-much-faster-than-capture-output/