Save animation into a movie file.
        
        [NOTE] If 'writer' is not specified, default writer defined in this module 
        will be used to generate the movie file.

        [TODO] Implement docstring inheritance.

def save(self, *args, **kwargs):
        """Save animation into a movie file.
        
        [NOTE] If 'writer' is not specified, default writer defined in this module 
        will be used to generate the movie file.

        [TODO] Implement docstring inheritance.
        """
        writer = None
        if 'writer' in kwargs.keys():
            writer = kwargs.pop('writer')
        else: writer = default_writer
        super().save(*args, **kwargs, writer=writer)