code: public FastqBuilder withQuality(final String quality)
  	{
  		if (quality == null)
  		{
  			throw new IllegalArgumentException("quality must not be null");
  		}
  		if (this.quality == null)
  		{
  			this.quality = new StringBuilder(quality.length());
  		}
  		this.quality.replace(0, this.quality.length(), quality);
  		return this;
  	}
docs: Return this FASTQ formatted sequence builder configured with the specified quality scores.
  
  @param quality quality scores for this FASTQ formatted sequence builder, must not be null
  @return this FASTQ formatted sequence builder configured with the specified quality scores