Change the order of priority

[MrSquaare]

Hello,

Currently having three sources to retrieve values (file, env, flag), I am looking for a way to get the following order of priority (from the lowest to the highest):
default (flag) - file - env - flag

Indeed, since the default values are defined in the FlagSet, they are in priority on file and env sources (so currently the priority order is as follows: file - env - default (flag) - flag)

Is it possible to achieve the expected result?

Thank you.