*   New endpoints in tf.strings namespace: `tf.strings.join` (corresponds to
        `tf.string_join`), `tf.strings.regex_replace`, `tf.strings.to_number`
        (corresponds to `tf.string_to_number`), `tf.strings.strip` (corresponds
        to `tf.string_strip`), `tf.strings.substr`, `tf.strings.to_hash_bucket`
        (corresponds to `tf.string_to_hash_bucket`),
        `tf.strings.to_hash_bucket_fast` (corresponds to