Returns a base directory in which to access application data such as icons that is customized for a particular user.
On UNIX platforms this is determined using the mechanisms described
XDG Base Directory Specification.
In this case the directory retrieved will be
On Windows it follows XDG Base Directory Specification if
is defined. If
XDG_DATA_HOME is undefined, the folder to use for local (as
opposed to roaming) application data is used instead. See the
Note that in this case on Windows it will be the same
The return value is cached and modifying it at runtime is not supported, as it’s not thread-safe to modify environment variables at runtime.