docs: def convert_symbol_to_entrezid(self, symbol):
          """Convert Symbol to Entrez Gene Id"""
          entrezdict = {}
          server = "http://rest.genenames.org/fetch/symbol/{0}".format(symbol)
          r = requests.get(server, headers={"Content-Type": "application/json"})
          if not r.ok:
              r.raise_for_status()
              sys.exit()
          response = r.text
          info = xmltodict.parse(response)
          for data in info['response']['result']['doc']['str']:
              if data['@name'] == 'entrez_id':
                  entrezdict[data['@name']] = data['#text']
              if data['@name'] == 'symbol':
                  entrezdict[data['@name']] = data['#text']
          return entrezdict