'Applies each step of the process if they have not already been
performed.
Returns Unicode output with applied styles.
>>> html = "<style>h1 { color:#ffcc00; }</style><h1>Hello World!</h1>"
>>> Pynliner().from_string(html).run()
u\'<h1 style="color: #fc0">Hello World!</h1>\''

def run(self):

    if (not self.soup):
        self._get_soup()
    if (not self.stylesheet):
        self._get_styles()
    self._apply_styles()
    return self._get_output()
