def save(self, filename=None):
        filename = Path(filename) if filename is not None else self.filename
        with filename.open("w") as f:
            f.write(self.yaml)
def activate(self, callingWindow, fullContext, mainItem, i):
        fitID = self.mainFrame.getActiveFit()
        Fit.getInstance().setAsPattern(fitID, mainItem)
        wx.PostEvent(self.mainFrame, GE.FitChanged(fitIDs=(fitID,)))