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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 batch_for_sv(samples):
 """Prepare a set of samples for parallel structural variant calling. CWL input target -- groups samples into batches and structural variant callers for parallel processing. """

    samples = cwlutils.assign_complex_to_samples(samples)
    to_process, extras, background = _batch_split_by_sv(samples, "standard")
    out = [cwlutils.samples_to_records(xs) for xs in to_process.values()] + extras
    return out