'Returns a dictionary with all firlds read from the \'.nfo\' file.
The keys are named as \'nfo_something\'.'

def get_fields_from_nfo_file(self):

    d = {}
    if (self._root is None):
        return d
    if (self._root.tag != u'movie'):
        return d
    for (name, values) in self._fields.items():
        multiple_bool = values[0]
        getter_func = values[1]
        nfo_field_name = u'nfo_{0}'.format(name)
        if multiple_bool:
            v = self._extract_multiple_field(name, getter_func)
        else:
            v = self._extract_single_field(name, getter_func)
        if (v is not None):
            d[nfo_field_name] = v
    return d
