umask settings ignored in cache directory creation

[karakusc]

In Linux the umask setting defines the default permissions for newly created files and directories. For instance umask 000 implies that newly created files and directories are created with open permissions by default. diskcache does not seem to respect this setting while creating the cache directory, as the permissions are hard-coded to 755:
https://github.com/grantjenks/python-diskcache/blob/master/diskcache/core.py#L447

Would it be possible to use the default permissions provided by the OS in creating the cache directory?