message: Allow turning off checkpointing for ShardedMutableDenseHashTable. Keep the checkpointing=True as the default.
diff: @@ -49,6 +49,7 @@ class ShardedMutableDenseHashTable(lookup.LookupInterface):
  default_value,
  empty_key,
  num_shards=1,
  + checkpoint=True,
  name='ShardedMutableHashTable'):
  with ops.name_scope(name, 'sharded_mutable_hash_table') as scope:
  super(ShardedMutableDenseHashTable, self).__init__(key_dtype,
  @@ -61,6 +62,7 @@ class ShardedMutableDenseHashTable(lookup.LookupInterface):
  value_dtype=value_dtype,
  default_value=default_value,
  empty_key=empty_key,
  + checkpoint=checkpoint,
  name='%s-%d-of-%d' % (name, i + 1, num_shards)))
  self._table_shards = table_shards
  # TODO(andreasst): add a value_shape() method to LookupInterface
  