Add a block_generator function. Fixes #11

4 jobs for block_gen in 31 minutes and 26 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Build
passed build_linux_27 #134994
docker

00:11:00

89.0%
passed build_linux_36 #134995
docker

00:10:46

89.0%
passed build_macosx_27 #134996
macosx

00:31:26

89.0%
passed build_macosx_36 #134997
macosx

00:30:38

89.0%