public GenomeSnippetSource(string chrom, IGenome genome, int genomeContextSize, int buffer = 300, ChrReference chrReference = null)
 {
     _genomeContextSize = genomeContextSize;
     _buffer            = buffer;
     if (chrReference != null)
     {
         _chrReference          = chrReference;
         _loadedOwnChrReference = false;
     }
     else
     {
         _chrReference          = genome.GetChrReference(chrom);
         _loadedOwnChrReference = true;
     }
 }