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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_batch_gender(items):
 """Retrieve gender for a batch of items if consistent. Better not to specify for mixed populations, CNVkit will work it out https://github.com/bcbio/bcbio-nextgen/commit/1a0e217c8a4d3cee10fa890fb3cfd4db5034281d#r26279752 """

    genders = set([population.get_gender(x) for x in items])
    if len(genders) == 1:
        gender = genders.pop()
        if gender != "unknown":
            return gender