code: def get_cytoBand_hg19(self):
          
          if self._cytoBand_hg19 is None:
              self._cytoBand_hg19 = self._load_cytoBand(self._get_path_cytoBand_hg19())
  
          return self._cytoBand_hg19
docs: Get UCSC cytoBand table for Build 37.
  
          Returns
          -------
          pandas.DataFrame
              cytoBand table if loading was successful, else None