<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def parse_cropbox(cropbox):
 """ Returns x, y, x2, y2 tuple for cropping. """

    if isinstance(cropbox, six.text_type):
        return tuple([int(x.strip()) for x in cropbox.split(',')])
    else:
        return tuple(cropbox)