code: def _lreg_bokeh(self, **kwargs):
          
          try:
              ds2 = self._duplicate_()
              ds2.timestamps(ds2.x)
              ds2.lreg("Timestamps", ds2.y)
              ds2.drop(ds2.y)
              ds2.df = ds2.df.rename(columns={'Regression': ds2.y})
              if "date_format" in self.chart_style:
                  ds2.date("Date", format=self.chart_style["date_format"])
              c = ds2.line_()
              return c
          except Exception as e:
              self.err(e, "Can not draw linear regression chart")
docs: Returns a Bokeh linear regression line