converts a style_dict to an openpyxl style object
        Parameters
        ----------
        style_dict : style dictionary to convert

def _convert_to_style(cls, style_dict):
        """
        converts a style_dict to an openpyxl style object
        Parameters
        ----------
        style_dict : style dictionary to convert
        """

        from openpyxl.style import Style
        xls_style = Style()
        for key, value in style_dict.items():
            for nk, nv in value.items():
                if key == "borders":
                    (xls_style.borders.__getattribute__(nk)
                     .__setattr__('border_style', nv))
                else:
                    xls_style.__getattribute__(key).__setattr__(nk, nv)

        return xls_style