'mount private directories'

def mountPrivateDirs(self):

    assert (not isinstance(self.privateDirs, basestring))
    for directory in self.privateDirs:
        if isinstance(directory, tuple):
            privateDir = (directory[1] % self.__dict__)
            mountPoint = directory[0]
            self.cmd(('mkdir    -p    %s' % privateDir))
            self.cmd(('mkdir    -p    %s' % mountPoint))
            self.cmd(('mount    --bind    %s    %s' % (privateDir, mountPoint)))
        else:
            self.cmd(('mkdir    -p    %s' % directory))
            self.cmd(('mount    -n    -t    tmpfs    tmpfs    %s' % directory))
