def collapse(self, start):
        if self.m_range is not None:
            collapse(self.m_range, start)
            self.m_startPoint = None

        elif start:
            self.m_endPoint = self.m_startPoint
        else:
            self.m_startPoint = self.m_endPoint
Collapses the range into a cursor, either to the start or end point
dataset/ETHPy150Open pyjs/pyjs/pyjswidgets/pyjamas/selection/Range.py/Range.collapse