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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 filter_variant_sequences( variant_sequences, preferred_sequence_length, min_variant_sequence_coverage=MIN_VARIANT_SEQUENCE_COVERAGE,):
 """ Drop variant sequences which are shorter than request or don't have enough supporting reads. """

    variant_sequences = trim_variant_sequences(
        variant_sequences, min_variant_sequence_coverage)

    return filter_variant_sequences_by_length(
        variant_sequences=variant_sequences,
        preferred_sequence_length=preferred_sequence_length)