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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 reads_generator_to_sequences_generator( variant_and_reads_generator, min_alt_rna_reads=MIN_ALT_RNA_READS, min_variant_sequence_coverage=MIN_VARIANT_SEQUENCE_COVERAGE, preferred_sequence_length=VARIANT_SEQUENCE_LENGTH, variant_sequence_assembly=VARIANT_SEQUENCE_ASSEMBLY):
 """ For each variant, collect all possible sequence contexts around the variant which are spanned by at least min_reads. Parameters variant_and_reads_generator : generator Sequence of Variant objects paired with a list of reads which overlap that variant. min_alt_rna_reads : int Minimum number of RNA reads supporting variant allele min_variant_sequence_coverage : int Minimum number of RNA reads supporting each nucleotide of the variant cDNA sequence sequence_length : int Desired sequence length, including variant nucleotides variant_sequence_assembly : bool Construct variant sequences by merging overlapping reads. If False then variant sequences must be fully spanned by cDNA reads. Yields pairs with the following fields: - Variant - list of VariantSequence objects """

    for variant, variant_reads in variant_and_reads_generator:
        variant_sequences = reads_to_variant_sequences(
            variant=variant,
            reads=variant_reads,
            min_alt_rna_reads=min_alt_rna_reads,
            min_variant_sequence_coverage=min_variant_sequence_coverage,
            preferred_sequence_length=preferred_sequence_length,
            variant_sequence_assembly=variant_sequence_assembly)
        yield variant, variant_sequences