Add a timestamps column from a date column

        :param col: name of the timestamps column to add
        :type col: str
        :param \*\*kwargs: keyword arguments for ``pd.to_datetime`` 
                                                                                                                                                                                                                                                                                                                                        for date conversions
        :type \*\*kwargs: optional

        :example: ``ds.timestamps("mycol")``

def timestamps(self, col: str, **kwargs):
        """"
        Add a timestamps column from a date column

        :param col: name of the timestamps column to add
        :type col: str
        :param \*\*kwargs: keyword arguments for ``pd.to_datetime`` 
                                                                                                                                                                                                                                                                                                                                        for date conversions
        :type \*\*kwargs: optional

        :example: ``ds.timestamps("mycol")``
        """
        try:
            name = "Timestamps"
            if "name" in kwargs:
                name = kwargs["name"]
            if "errors" not in kwargs:
                kwargs["errors"] = "coerce"
            if "unit" in kwargs:
                kwargs["unit"] = "ms"
            try:
                self.df[col] = pd.to_datetime(self.df[col], **kwargs)
            except TypeError:
                pass
            ts = []
            for el in self.df[col]:
                ts.append(arrow.get(el).timestamp)
            self.df[name] = ts
        except Exception as e:
            self.err(e, "Can not convert to timestamps")