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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def clear_tab_stop(self, how=0):
 """Clear a horizontal tab stop. :param int how: defines a way the tab stop should be cleared: * ``0`` or nothing -- Clears a horizontal tab stop at cursor position. * ``3`` -- Clears all horizontal tab stops. """

        if how == 0:
            # Clears a horizontal tab stop at cursor position, if it's
            # present, or silently fails if otherwise.
            self.tabstops.discard(self.cursor.x)
        elif how == 3:
            self.tabstops = set()