repeatRange: '{' INTEGER (',' (INTEGER | UNBOUNDED)? '}'

def visitMinMaxRange(self, ctx: ShExDocParser.MinMaxRangeContext):
        """ repeatRange: '{' INTEGER (',' (INTEGER | UNBOUNDED)? '}' """
        self.expression.min = int(ctx.INTEGER(0).getText())
        self.expression.max = int(ctx.INTEGER(1).getText()) if len(ctx.INTEGER()) > 1 else -1