message: revert wrong typo fix
diff: @@ -508,7 +508,7 @@ is sufficient. However, TensorFlow also provides methods for manipulating
  the default graph, which can be useful in more advanced use cases. For example:
  * A @{tf.Graph} defines the namespace for @{tf.Operation} objects: each
  - operation in a single graph must have an unique name. TensorFlow will
  + operation in a single graph must have a unique name. TensorFlow will
  "uniquify" the names of operations by appending `"_1"`, `"_2"`, and so on to
  their names if the requested name is already taken. Using multiple explicitly
  created graphs gives you more control over what name is given to each
  