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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 greedy_merge( variant_sequences, min_overlap_size=MIN_VARIANT_SEQUENCE_ASSEMBLY_OVERLAP_SIZE):
 """ Greedily merge overlapping sequences into longer sequences. Accepts a collection of VariantSequence objects and returns another collection of elongated variant sequences. The reads field of the returned VariantSequence object will contain reads which only partially overlap the full sequence. """

    merged_any = True
    while merged_any:
        variant_sequences, merged_any = greedy_merge_helper(
            variant_sequences,
            min_overlap_size=min_overlap_size)
    return variant_sequences