<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_parallel_regions_block(batch):
 """CWL target to retrieve block group of callable regions for parallelization. Uses blocking to handle multicore runs. """

    samples = [utils.to_single_data(d) for d in batch]
    regions = _get_parallel_regions(samples[0])
    out = []
    # Currently don't have core information here so aim for about 10 items per partition
    n = 10
    for region_block in tz.partition_all(n, regions):
        out.append({"region_block": ["%s:%s-%s" % (c, s, e) for c, s, e in region_block]})
    return out