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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 strelka_somatic_variant_stats(variant, variant_metadata):
 """Parse out the variant calling statistics for a given variant from a Strelka VCF Parameters variant : varcode.Variant sample_info : dict Dictionary of sample to variant calling statistics, corresponds to the sample columns in a Strelka VCF Returns ------- SomaticVariantStats """


    sample_info = variant_metadata["sample_info"]
    # Ensure there are exactly two samples in the VCF, a tumor and normal
    assert len(sample_info) == 2, "More than two samples found in the somatic VCF"
    tumor_stats = _strelka_variant_stats(variant, sample_info["TUMOR"])
    normal_stats = _strelka_variant_stats(variant, sample_info["NORMAL"])
    return SomaticVariantStats(tumor_stats=tumor_stats, normal_stats=normal_stats)