/usr/bin/maas is in maas-cli 1.5.4+bzr2294-0ubuntu1.2.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 | #!/bin/sh
if [ "`expr \"$0\" : \".*maas-cli*\"`" != "0" ];then
    echo "  WARNING: The maas-cli command is deprecated and will be removed" \
         "in a future\n  version.  From now on please use 'maas' instead." >&2
fi
exec python -m maascli "$@"
 |