'Offsets multiple keys by a delta, incrementing and decrementing in batch.
Args:
mapping: Dictionary mapping keys to deltas (positive or negative integers)
to apply to each corresponding key.
key_prefix: Prefix for to prepend to all keys.
initial_value: Initial value to put in the cache, if it doesn\'t
already exist. The default value, None, will not create a cache
entry if it doesn\'t already exist.
namespace: A string specifying an optional namespace to use in
the request.
Returns:
Dictionary mapping input keys to new integer values. The new value will
be None if an error occurs, the key does not already exist, or the value
was not an integer type. The values will wrap-around at unsigned 64-bit
integer-maximum and underflow will be floored at zero.'

def offset_multi(self, mapping, key_prefix='', namespace=None, initial_value=None):

    rpc = self.offset_multi_async(mapping, key_prefix, namespace, initial_value)
    return rpc.get_result()
