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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 trim_variant_sequences(variant_sequences, min_variant_sequence_coverage):
 """ Trim VariantSequences to desired coverage and then combine any subsequences which get generated. """

    n_total = len(variant_sequences)
    trimmed_variant_sequences = [
        variant_sequence.trim_by_coverage(min_variant_sequence_coverage)
        for variant_sequence in variant_sequences
    ]
    collapsed_variant_sequences = collapse_substrings(trimmed_variant_sequences)
    n_after_trimming = len(collapsed_variant_sequences)
    logger.info(
        "Kept %d/%d variant sequences after read coverage trimming to >=%dx",
        n_after_trimming,
        n_total,
        min_variant_sequence_coverage)
    return collapsed_variant_sequences