class_docstr: Sequence-to-sequence base class.
class_docstr_tok: ["Sequence-to-sequence","base","class","."]
docstr: Subclass must implement this.
  
  Build and run an RNN encoder.
  
  Args:
    hparams: Hyperparameters configurations.
  
  Returns:
    A tuple of encoder_outputs and encoder_state.
docstr_tok: ["Subclass","must","implement","this",".","Build","and","run","an","RNN","encoder",".","Args",":","hparams",":","Hyperparameters","configurations",".","Returns",":","A","tuple","of","encoder_outputs","and","encoder_state","."]
code: def _build_encoder(self, hparams):
      """Subclass must implement this.
  
      Build and run an RNN encoder.
  
      Args:
        hparams: Hyperparameters configurations.
  
      Returns:
        A tuple of encoder_outputs and encoder_state.
      """
      pass
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import abc
  import collections
  import tensorflow
  from tensorflow.contrib.model_pruning import get_masks, get_thresholds
  from tensorflow.contrib.model_pruning.python import pruning
  from tensorflow.contrib.model_pruning.python.layers import core_layers
  from .None import model_helper
  from .utils import misc_utils, iterator_utils
label_desc: Use image node_id 12 for calling the BaseModel obj's underlying member method code with example usage: obj._build_encoder(hparams) without return types