1) Create a py project and paste the following code block

def update(self, event):
        context = {}
        exec self.execentry.text in context
        each = compile(self.evalentry.text, '<input>', 'eval')
        numbers = [0]*self.numelements
        for x in xrange(self.numelements):
            context['x'] = float(x)
            numbers[x] = eval(each, context)
        self.chart.data = numbers
        if self.chart.style == 'Line':
            self.line.setSelected(1)
        else:
            self.filled.setSelected(1)
        self.chart.repaint()

2) Double click on the 'Line'(line 10) code and right click and select rename and it will display an error message on 
bottom of the editor saying "cannot perform rename here" in red
3) Now double click the "each" variable in line 4 and right clik and select rename it will allow you to rename but 
still that error message is displayed at the bottom of the editor

see the attached acreen shot. using build 62.