Adapted RJ's code to cmapper.
Adapted RJ's code to cmapper.


Former-commit-id: 98c8e181e13fd8902bc6dba57171818544079aa7
neurodata/ndgrutedb,neurodata/ndgrutedb,neurodata/ndgrutedb,neurodata/ndgrutedb,openconnectome/m2g,openconnectome/m2g,openconnectome/m2g,neurodata/ndgrutedb,openconnectome/m2g,neurodata/ndgrutedb,neurodata/ndgrutedb,neurodata/ndgrutedb,openconnectome/m2g,openconnectome/m2g,openconnectome/m2g,neurodata/ndmg,openconnectome/m2g