Fix documentation error

5 jobs for ImproveTrainerFunction in 77 minutes and 17 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #246850
docker
build_linux_38

00:27:04

70.0%
passed #246864
intel macos
build_macos_intel_38

00:50:12

70.0%
failed #246843
docker
build_linux_38

00:14:37

70.0%
failed #246851
intel macos
build_macos_intel_38

01:00:19

failed #246842
intel macos
build_macos_intel_38

01:00:00

70.0%