:param extra_classes: String with space separated list of classes or None

def get_input_column_attributes(self, extra_classes=None):
        """
        :param extra_classes: String with space separated list of classes or None
        """
        all_classes = []
        css_class = self.input_column_class
        if css_class:
            all_classes.append(css_class)
        if extra_classes:
            all_classes.append(extra_classes)

        style = self.input_column_style
        parts = []

        if all_classes:
            parts.append('class="{}"'.format(' '.join(all_classes)))

        if style:
            parts.append('style="{}"'.format(style))

        return Markup(' '.join(parts))