Own check for monitoring total disk usage of a host not working

Troubleshooting
14

If i use your code, i first get one new check found.

cmk --debug -vvI testhost

  1 filesystem_df_total
SUCCESS - Found 1 services

also the check gave the expected output

cmk --debug -vvn testhost
...
<<<filesystem_df_total>>> / Transition HostSectionParser -> HostSectionParser
...
No persisted sections
  -> Add sections: [... 'filesystem_df_total', ...]

Filesystem total     Here Iam