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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 get_row_generator(self, ref, cache=None):
 """Return a row generator for a reference"""

        from inspect import isgenerator
        from rowgenerators import get_generator

        g = get_generator(ref)

        if not g:
            raise GenerateError("Cant figure out how to generate rows from {} ref: {}".format(type(ref), ref))
        else:
            return g