# coding=utf-8
# Copyright 2018 Salesforce and HuggingFace Inc. team.
# Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
""" TF 2.0 CTRL model."""
import logging
import numpy as np
import tensorflow as tf
from .configuration_ctrl import CTRLConfig
from .file_utils import add_start_docstrings, add_start_docstrings_to_callable
from .modeling_tf_utils import TFPreTrainedModel, TFSharedEmbeddings, keras_serializable, shape_list
from .tokenization_utils import BatchEncoding
logger = logging.getLogger(__name__)
TF_CTRL_PRETRAINED_MODEL_ARCHIVE_MAP = {"ctrl": "https://cdn.huggingface.co/ctrl-tf_model.h5"}
def angle_defn(pos, i, d_model_size):
angle_rates = 1 / np.power(10000, (2 * (i // 2)) / np.float32(d_model_size))
return pos * angle_rates
def positional_encoding(position, d_model_size):
# create the sinusoidal pattern for the positional encoding
angle_rads = angle_defn(np.arange(position)[:, np.newaxis], np.arange(d_model_size)[np.newaxis, :], d_model_size)
sines = np.sin(angle_rads[:, 0::2])
cosines = np.cos(angle_rads[:, 1::2])
# pos_encoding = tf.cast(np.concatenate([sines, cosines], axis=-1)[np.newaxis, ...], dtype=tf.float32)
pos_encoding = tf.cast(np.concatenate([sines, cosines], axis=-1), dtype=tf.float32)
return pos_encoding
def scaled_dot_product_attention(q, k, v, mask, attention_mask=None, head_mask=None):
# calculate attention
matmul_qk = tf.matmul(q, k, transpose_b=True)
dk = tf.cast(shape_list(k)[-1], tf.float32)
scaled_attention_logits = matmul_qk / tf.math.sqrt(dk)
if mask is not None:
scaled_attention_logits += mask * -1e4
if attention_mask is not None:
# Apply the attention mask
scaled_attention_logits = scaled_attention_logits + attention_mask
attention_weights = tf.nn.softmax(scaled_attention_logits, axis=-1)
# Mask heads if we want to
if head_mask is not None:
attention_weights = attention_weights * head_mask
output = tf.matmul(attention_weights, v)
return output, attention_weights
class TFMultiHeadAttention(tf.keras.layers.Layer):
def __init__(self, d_model_size, num_heads, output_attentions=False, **kwargs):
super().__init__(**kwargs)
self.output_attentions = output_attentions
self.num_heads = num_heads
self.d_model_size = d_model_size
self.depth = int(d_model_size / self.num_heads)
self.Wq = tf.keras.layers.Dense(d_model_size, name="Wq")
self.Wk = tf.keras.layers.Dense(d_model_size, name="Wk")
self.Wv = tf.keras.layers.Dense(d_model_size, name="Wv")
self.dense = tf.keras.layers.Dense(d_model_size, name="dense")
def split_into_heads(self, x, batch_size):
x = tf.reshape(x, (batch_size, -1, self.num_heads, self.depth))
return tf.transpose(x, perm=[0, 2, 1, 3])
def call(self, inputs, training=False):
v, k, q, mask, layer_past, attention_mask, head_mask, use_cache = inputs
batch_size = shape_list(q)[0]
q = self.Wq(q)
k = self.Wk(k)
v = self.Wv(v)
q = self.split_into_heads(q, batch_size)
k = self.split_into_heads(k, batch_size)
v = self.split_into_heads(v, batch_size)
if layer_past is not None:
past_key, past_value = tf.unstack(layer_past, axis=0)
k = tf.concat((past_key, k), axis=-2)
v = tf.concat((past_value, v), axis=-2)
# to cope with keras serialization
# we need to cast `use_cache` to correct bool
# if it is a tensor
if tf.is_tensor(use_cache):
if hasattr(use_cache, "numpy"):
use_cache = bool(use_cache.numpy())
else:
use_cache = True
if use_cache is True:
present = tf.stack((k, v), axis=0)
else:
present = (None,)
output = scaled_dot_product_attention(q, k, v, mask, attention_mask, head_mask)
scaled_attention = tf.transpose(output[0], perm=[0, 2, 1, 3])
attn = output[1]
original_size_attention = tf.reshape(scaled_attention, (batch_size, -1, self.d_model_size))
output = self.dense(original_size_attention)
outputs = (output, present)
if self.output_attentions:
outputs = outputs + (attn,)
return outputs
def point_wise_feed_forward_network(d_model_size, dff, name=""):
return tf.keras.Sequential(
[tf.keras.layers.Dense(dff, activation="relu", name="0"), tf.keras.layers.Dense(d_model_size, name="2")],
name="ffn",
)
class TFEncoderLayer(tf.keras.layers.Layer):
def __init__(
self, d_model_size, num_heads, dff, rate=0.1, layer_norm_epsilon=1e-6, output_attentions=False, **kwargs
):
super().__init__(**kwargs)
self.multi_head_attention = TFMultiHeadAttention(
d_model_size, num_heads, output_attentions, name="multi_head_attention"
)
self.ffn = point_wise_feed_forward_network(d_model_size, dff, name="ffn")
self.layernorm1 = tf.keras.layers.LayerNormalization(epsilon=layer_norm_epsilon, name="layernorm1")
self.layernorm2 = tf.keras.layers.LayerNormalization(epsilon=layer_norm_epsilon, name="layernorm2")
self.dropout1 = tf.keras.layers.Dropout(rate)
self.dropout2 = tf.keras.layers.Dropout(rate)
def call(self, inputs, training=False):
x, mask, layer_past, attention_mask, head_mask, use_cache = inputs
normed = self.layernorm1(x)
attn_outputs = self.multi_head_attention(
[normed, normed, normed, mask, layer_past, attention_mask, head_mask, use_cache], training=training
)
attn_output = attn_outputs[0]
attn_output = self.dropout1(attn_output, training=training)
out1 = x + attn_output
out2 = self.layernorm2(out1)
ffn_output = self.ffn(out2)
ffn_output = self.dropout2(ffn_output, training=training)
out2 = out1 + ffn_output
outputs = (out2,) + attn_outputs[1:]
return outputs
@keras_serializable
class TFCTRLMainLayer(tf.keras.layers.Layer):
config_class = CTRLConfig
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.output_hidden_states = config.output_hidden_states
self.output_attentions = config.output_attentions
self.d_model_size = config.n_embd
self.num_layers = config.n_layer
self.pos_encoding = positional_encoding(config.n_positions, self.d_model_size)
self.w = TFSharedEmbeddings(
config.vocab_size, config.n_embd, initializer_range=config.initializer_range, name="w"
)
self.dropout = tf.keras.layers.Dropout(config.embd_pdrop)
self.h = [
TFEncoderLayer(
config.n_embd,
config.n_head,
config.dff,
config.resid_pdrop,
config.layer_norm_epsilon,
config.output_attentions,
name="h_._{}".format(i),
)
for i in range(config.n_layer)
]
self.layernorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_epsilon, name="layernorm")
def get_input_embeddings(self):
return self.w
def _resize_token_embeddings(self, new_num_tokens):
raise NotImplementedError
def _prune_heads(self, heads_to_prune):
""" Prunes heads of the model.
heads_to_prune: dict of {layer_num: list of heads to prune in this layer}
"""
raise NotImplementedError
def call(
self,
inputs,
past=None,
attention_mask=None,
token_type_ids=None,
position_ids=None,
head_mask=None,
inputs_embeds=None,
use_cache=True,
training=False,
):
if isinstance(inputs, (tuple, list)):
input_ids = inputs[0]
past = inputs[1] if len(inputs) > 1 else past
attention_mask = inputs[2] if len(inputs) > 2 else attention_mask
token_type_ids = inputs[3] if len(inputs) > 3 else token_type_ids
position_ids = inputs[4] if len(inputs) > 4 else position_ids
head_mask = inputs[5] if len(inputs) > 5 else head_mask
inputs_embeds = inputs[6] if len(inputs) > 6 else inputs_embeds
use_cache = inputs[7] if len(inputs) > 7 else use_cache
assert len(inputs) <= 8, "Too many inputs."
elif isinstance(inputs, (dict, BatchEncoding)):
input_ids = inputs.get("input_ids")
past = inputs.get("past", past)
attention_mask = inputs.get("attention_mask", attention_mask)
token_type_ids = inputs.get("token_type_ids", token_type_ids)
position_ids = inputs.get("position_ids", position_ids)
head_mask = inputs.get("head_mask", head_mask)
inputs_embeds = inputs.get("inputs_embeds", inputs_embeds)
use_cache = inputs.get("use_cache", use_cache)
assert len(inputs) <= 8, "Too many inputs."
else:
input_ids = inputs
# If using past key value states, only the last tokens
# should be given as an input
if past is not None:
if input_ids is not None:
input_ids = input_ids[:, -1:]
if inputs_embeds is not None:
inputs_embeds = inputs_embeds[:, -1:]
if token_type_ids is not None:
token_type_ids = token_type_ids[:, -1:]
if input_ids is not None and inputs_embeds is not None:
raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time")
elif input_ids is not None:
input_shape = shape_list(input_ids)
input_ids = tf.reshape(input_ids, [-1, input_shape[-1]])
elif inputs_embeds is not None:
input_shape = shape_list(inputs_embeds)[:-1]
else:
raise ValueError("You have to specify either input_ids or inputs_embeds")
if past is None:
past_length = 0
past = [None] * len(self.h)
else:
past_length = shape_list(past[0][0])[-2]
if position_ids is None:
position_ids = tf.range(past_length, input_shape[-1] + past_length, dtype=tf.int32)[tf.newaxis, :]
position_ids = tf.tile(position_ids, [input_shape[0], 1])
# Attention mask.
if attention_mask is not None:
# We create a 3D attention mask from a 2D tensor mask.
# Sizes are [batch_size, 1, 1, to_seq_length]
# So we can broadcast to [batch_size, num_heads, from_seq_length, to_seq_length]
# this attention mask is more simple than the triangular masking of causal attention
# used in OpenAI GPT, we just need to prepare the broadcast dimension here.
attention_mask = attention_mask[:, tf.newaxis, tf.newaxis, :]
# Since attention_mask is 1.0 for positions we want to attend and 0.0 for
# masked positions, this operation will create a tensor which is 0.0 for
# positions we want to attend and -10000.0 for masked positions.
# Since we are adding it to the raw scores before the softmax, this is
# effectively the same as removing these entirely.
attention_mask = tf.cast(attention_mask, tf.float32)
attention_mask = (1.0 - attention_mask) * -10000.0
else:
attention_mask = None
# Prepare head mask if needed
# 1.0 in head_mask indicate we keep the head
# attention_probs has shape bsz x n_heads x N x N
# head_mask has shape n_layer x batch x n_heads x N x N
if head_mask is not None:
raise NotImplementedError
else:
head_mask = [None] * self.num_layers
if token_type_ids is not None:
token_type_ids = tf.reshape(token_type_ids, [-1, shape_list(token_type_ids)[-1]])
token_type_embeds = self.w(token_type_ids, mode="embedding")
token_type_embeds *= tf.math.sqrt(tf.cast(self.d_model_size, tf.float32))
else:
token_type_embeds = 0
position_ids = tf.reshape(position_ids, [-1, shape_list(position_ids)[-1]])
if inputs_embeds is None:
inputs_embeds = self.w(input_ids, mode="embedding")
seq_len = input_shape[-1]
mask = 1 - tf.linalg.band_part(tf.ones((seq_len, seq_len)), -1, 0)
inputs_embeds *= tf.math.sqrt(tf.cast(self.d_model_size, tf.float32))
pos_embeds = tf.gather(self.pos_encoding, position_ids)
hidden_states = inputs_embeds + pos_embeds + token_type_embeds
hidden_states = self.dropout(hidden_states, training=training)
output_shape = input_shape + [shape_list(hidden_states)[-1]]
presents = ()
all_hidden_states = ()
all_attentions = []
for i, (h, layer_past) in enumerate(zip(self.h, past)):
if self.output_hidden_states:
all_hidden_states = all_hidden_states + (tf.reshape(hidden_states, output_shape),)
outputs = h([hidden_states, mask, layer_past, attention_mask, head_mask[i], use_cache], training=training)
hidden_states, present = outputs[:2]
if use_cache is True:
presents = presents + (present,)
if self.output_attentions:
all_attentions.append(outputs[2])
hidden_states = self.layernorm(hidden_states)
hidden_states = tf.reshape(hidden_states, output_shape)
if self.output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
outputs = (hidden_states,)
if use_cache is True:
outputs = outputs + (presents,)
if self.output_hidden_states:
outputs = outputs + (all_hidden_states,)
if self.output_attentions:
# let the number of heads free (-1) so we can extract attention even after head pruning
attention_output_shape = input_shape[:-1] + [-1] + shape_list(all_attentions[0])[-2:]
all_attentions = tuple(tf.reshape(t, attention_output_shape) for t in all_attentions)
outputs = outputs + (all_attentions,)
return outputs
class TFCTRLPreTrainedModel(TFPreTrainedModel):
""" An abstract class to handle weights initialization and
a simple interface for downloading and loading pretrained models.
"""
config_class = CTRLConfig
pretrained_model_archive_map = TF_CTRL_PRETRAINED_MODEL_ARCHIVE_MAP
base_model_prefix = "transformer"
CTRL_START_DOCSTRING = r"""
.. note::
TF 2.0 models accepts two formats as inputs:
- having all inputs as keyword arguments (like PyTorch models), or
- having all inputs as a list, tuple or dict in the first positional arguments.
This second option is useful when using :obj:`tf.keras.Model.fit()` method which currently requires having
all the tensors in the first argument of the model call function: :obj:`model(inputs)`.
If you choose this second option, there are three possibilities you can use to gather all the input Tensors
in the first positional argument :
- a single Tensor with input_ids only and nothing else: :obj:`model(inputs_ids)`
- a list of varying length with one or several input Tensors IN THE ORDER given in the docstring:
:obj:`model([input_ids, attention_mask])` or :obj:`model([input_ids, attention_mask, token_type_ids])`
- a dictionary with one or several input Tensors associated to the input names given in the docstring:
:obj:`model({'input_ids': input_ids, 'token_type_ids': token_type_ids})`
Parameters:
config (:class:`~transformers.CTRLConfig`): Model configuration class with all the parameters of the model.
Initializing with a config file does not load the weights associated with the model, only the configuration.
Check out the :meth:`~transformers.PreTrainedModel.from_pretrained` method to load the model weights.
"""
CTRL_INPUTS_DOCSTRING = r"""
Args:
input_ids (:obj:`Numpy array` or :obj:`tf.Tensor` of shape :obj:`(batch_size, sequence_length)`):
Indices of input sequence tokens in the vocabulary.
If `past` is used, optionally only the last `input_ids` have to be input (see `past`).
Indices can be obtained using :class:`transformers.CTRLTokenizer`.
See :func:`transformers.PreTrainedTokenizer.encode` and
:func:`transformers.PreTrainedTokenizer.encode_plus` for details.
`What are input IDs? <../glossary.html#input-ids>`__
past (:obj:`List[tf.Tensor]` of length :obj:`config.n_layers`):
Contains pre-computed hidden-states (key and values in the attention blocks) as computed by the model
(see `past` output below). Can be used to speed up sequential decoding.
If `past` is used, the user can optionally input only the last `input_ids`
(those that don't have their past given to this model) of shape :obj:`(batch_size, 1)`
instead of all `input_ids` of shape :obj:`(batch_size, sequence_length)`.
attention_mask (:obj:`tf.Tensor` or :obj:`Numpy array` of shape :obj:`(batch_size, sequence_length)`, `optional`, defaults to :obj:`None`):
Mask to avoid performing attention on padding token indices.
Mask values selected in ``[0, 1]``:
``1`` for tokens that are NOT MASKED, ``0`` for MASKED tokens.
`What are attention masks? <../glossary.html#attention-mask>`__
token_type_ids (:obj:`tf.Tensor` or :obj:`Numpy array` of shape :obj:`(batch_size, sequence_length)`, `optional`, defaults to :obj:`None`):
Segment token indices to indicate first and second portions of the inputs.
Indices are selected in ``[0, 1]``: ``0`` corresponds to a `sentence A` token, ``1``
corresponds to a `sentence B` token
If `past` is used, optionally only the last `token_type_ids` have to be input (see `past`).
`What are token type IDs? <../glossary.html#token-type-ids>`_
position_ids (:obj:`tf.Tensor` or :obj:`Numpy array` of shape :obj:`(batch_size, sequence_length)`, `optional`, defaults to :obj:`None`):
Indices of positions of each input sequence tokens in the position embeddings.
Selected in the range ``[0, config.max_position_embeddings - 1]``.
`What are position IDs? <../glossary.html#position-ids>`_
head_mask (:obj:`tf.Tensor` or :obj:`Numpy array` of shape :obj:`(num_heads,)` or :obj:`(num_layers, num_heads)`, `optional`, defaults to :obj:`None`):
Mask to nullify selected heads of the self-attention modules.
Mask values selected in ``[0, 1]``:
:obj:`1` indicates the head is **not masked**, :obj:`0` indicates the head is **masked**.
input_embeds (:obj:`tf.Tensor` or :obj:`Numpy array` of shape :obj:`(batch_size, sequence_length, hidden_size)`, `optional`, defaults to :obj:`None`):
Optionally, instead of passing :obj:`input_ids` you can choose to directly pass an embedded representation.
This is useful if you want more control over how to convert `input_ids` indices into associated vectors
than the model's internal embedding lookup matrix.
If `past` is used, optionally only the last `input_embeds` have to be input (see `past`).
use_cache (:obj:`bool`):
If `use_cache` is True, `past` key value states are returned and
can be used to speed up decoding (see `past`). Defaults to `True`.
training (:obj:`boolean`, `optional`, defaults to :obj:`False`):
Whether to activate dropout modules (if set to :obj:`True`) during training or to de-activate them
(if set to :obj:`False`) for evaluation.
"""
[docs]@add_start_docstrings(
"The bare CTRL Model transformer outputting raw hidden-states without any specific head on top.",
CTRL_START_DOCSTRING,
)
class TFCTRLModel(TFCTRLPreTrainedModel):
def __init__(self, config, *inputs, **kwargs):
super().__init__(config, *inputs, **kwargs)
self.transformer = TFCTRLMainLayer(config, name="transformer")
[docs] @add_start_docstrings_to_callable(CTRL_INPUTS_DOCSTRING)
def call(self, inputs, **kwargs):
r"""
Return:
:obj:`tuple(tf.Tensor)` comprising various elements depending on the configuration (:class:`~transformers.CTRLConfig`) and inputs:
last_hidden_state (:obj:`tf.Tensor` of shape :obj:`(batch_size, sequence_length, hidden_size)`):
Sequence of hidden-states at the last layer of the model.
past (:obj:`List[tf.Tensor]` of length :obj:`config.n_layers` with each tensor of shape :obj:`(2, batch_size, num_heads, sequence_length, embed_size_per_head)`):
Contains pre-computed hidden-states (key and values in the attention blocks).
Can be used (see `past` input) to speed up sequential decoding. The token ids which have their past given to this model
should not be passed as input ids as they have already been computed.
hidden_states (:obj:`tuple(tf.Tensor)` `optional`, returned when ``config.output_hidden_states=True``):
Tuple of :obj:`tf.Tensor` (one for the output of the embeddings + one for the output of each layer)
of shape :obj:`(batch_size, sequence_length, hidden_size)`.
Hidden-states of the model at the output of each layer plus the initial embedding outputs.
attentions (:obj:`tuple(tf.Tensor)`, `optional`, returned when ``config.output_attentions=True``):
Tuple of :obj:`tf.Tensor` (one for each layer) of shape
:obj:`(batch_size, num_heads, sequence_length, sequence_length)`.
Attentions weights after the attention softmax, used to compute the weighted average in the self-attention
heads.
Examples::
import tensorflow as tf
from transformers import CTRLTokenizer, TFCTRLModel
tokenizer = CTRLTokenizer.from_pretrained('ctrl')
model = TFCTRLModel.from_pretrained('ctrl')
input_ids = tf.constant(tokenizer.encode("Hello, my dog is cute", add_special_tokens=True))[None, :] # Batch size 1
outputs = model(input_ids)
last_hidden_states = outputs[0] # The last hidden-state is the first element of the output tuple
"""
outputs = self.transformer(inputs, **kwargs)
return outputs
class TFCTRLLMHead(tf.keras.layers.Layer):
def __init__(self, config, input_embeddings, **kwargs):
super().__init__(**kwargs)
self.vocab_size = config.vocab_size
# The output weights are the same as the input embeddings, but there is
# an output-only bias for each token.
self.input_embeddings = input_embeddings
def build(self, input_shape):
self.bias = self.add_weight(shape=(self.vocab_size,), initializer="zeros", trainable=True, name="bias")
super().build(input_shape)
def call(self, hidden_states):
hidden_states = self.input_embeddings(hidden_states, mode="linear")
hidden_states = hidden_states + self.bias
return hidden_states
[docs]@add_start_docstrings(
"""The CTRL Model transformer with a language modeling head on top
(linear layer with weights tied to the input embeddings). """,
CTRL_START_DOCSTRING,
)
class TFCTRLLMHeadModel(TFCTRLPreTrainedModel):
def __init__(self, config, *inputs, **kwargs):
super().__init__(config, *inputs, **kwargs)
self.transformer = TFCTRLMainLayer(config, name="transformer")
self.lm_head = TFCTRLLMHead(config, self.transformer.w, name="lm_head")
[docs] def get_output_embeddings(self):
return self.lm_head.input_embeddings
def prepare_inputs_for_generation(self, inputs, past, **kwargs):
# only last token for inputs_ids if past is defined in kwargs
if past:
inputs = tf.expand_dims(inputs[:, -1], -1)
return {"inputs": inputs, "past": past, "use_cache": kwargs["use_cache"]}
[docs] @add_start_docstrings_to_callable(CTRL_INPUTS_DOCSTRING)
def call(self, inputs, **kwargs):
r"""
Return:
:obj:`tuple(tf.Tensor)` comprising various elements depending on the configuration (:class:`~transformers.CTRLConfig`) and inputs:
prediction_scores (:obj:`tf.Tensor` of shape :obj:`(batch_size, sequence_length, config.vocab_size)`):
Prediction scores of the language modeling head (scores for each vocabulary token before SoftMax).
past (:obj:`List[tf.Tensor]` of length :obj:`config.n_layers` with each tensor of shape :obj:`(2, batch_size, num_heads, sequence_length, embed_size_per_head)`):
Contains pre-computed hidden-states (key and values in the attention blocks).
Can be used (see `past` input) to speed up sequential decoding. The token ids which have their past given to this model
should not be passed as input ids as they have already been computed.
hidden_states (:obj:`tuple(tf.Tensor)`, `optional`, returned when ``config.output_hidden_states=True``):
Tuple of :obj:`tf.Tensor` (one for the output of the embeddings + one for the output of each layer)
of shape :obj:`(batch_size, sequence_length, hidden_size)`.
Hidden-states of the model at the output of each layer plus the initial embedding outputs.
attentions (:obj:`tuple(tf.Tensor)`, `optional`, returned when ``config.output_attentions=True``):
Tuple of :obj:`tf.Tensor` (one for each layer) of shape
:obj:`(batch_size, num_heads, sequence_length, sequence_length)`.
Attentions weights after the attention softmax, used to compute the weighted average in the self-attention
heads.
Examples::
import tensorflow as tf
from transformers import CTRLTokenizer, TFCTRLLMHeadModel
tokenizer = CTRLTokenizer.from_pretrained('ctrl')
model = TFCTRLLMHeadModel.from_pretrained('ctrl')
input_ids = tf.constant([tokenizer.encode("Links Hello, my dog is cute", add_special_tokens=True)])
outputs = model(input_ids)
loss, logits = outputs[:2]
"""
transformer_outputs = self.transformer(inputs, **kwargs)
hidden_states = transformer_outputs[0]
lm_logits = self.lm_head(hidden_states)
outputs = (lm_logits,) + transformer_outputs[1:]
return outputs # lm_logits, presents, (all hidden_states), (attentions)