code: def get_response(self, data_type=None):
          
          if not data_type:
              return self.cache.get_response(r_type='ticker') or self.cache.get_response(r_type='global')
          elif data_type == 'ticker':
              return self.cache.get_response(r_type='ticker')
          return self.cache.get_response(r_type='global')
docs: return json response from APIs converted into python list
             : param string 'data_type', if it's None it'll return the avaliable cache,
              if we've both global and ticker data, the function will return 'ticker' data,
              in that case, data_type should be assigned with 'ticker' or 'global'