code: def map_boto_exceptions(key=None, exc_pass=()):
      
      from boto.exception import BotoClientError, BotoServerError, \
          StorageResponseError
      try:
          yield
      except StorageResponseError as e:
          if e.code == 'NoSuchKey':
              raise KeyError(key)
          raise IOError(str(e))
      except (BotoClientError, BotoServerError) as e:
          if e.__class__.__name__ not in exc_pass:
              raise IOError(str(e))
docs: Map boto-specific exceptions to the simplekv-API.