Fix doctests

3 jobs for master in 39 minutes and 35 seconds (queued for 4 seconds)
latest
Status Name Job ID Coverage
  Test
passed job_clang_amd64 #5796
amd64

00:39:35

passed job_clang_cxx_amd64 #5797
amd64

00:13:05

passed job_gcc_amd64 #5795
amd64

00:36:49