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