'Print out each added key and each overriden key.'

def override_opt(self, new_opt):

    for (k, v) in new_opt.items():
        if (k not in self.opt):
            print 'Adding    new    option    [    {k}:    {v}    ]'.format(k=k, v=v)
        elif (self.opt[k] != v):
            print 'Overriding    option    [    {k}:    {old}    =>    {v}]'.format(k=k, old=self.opt[k], v=v)
        self.opt[k] = v
    return self.opt
