docs: def get_chromosomes(self, sv=False):
          """Return a list of all chromosomes found in database
          
          Args:
              sv(bool): if sv variants should be choosen
          
          Returns:
              res(iterable(str)): An iterable with all chromosomes in the database
          """
          if sv:
              res = self.db.structural_variant.distinct('chrom')
          else:
              res = self.db.variant.distinct('chrom')
              
          return res