docstr: NER evaluator for data preprocess
  :param list[Sample] data_samples: list of Samples
  :return: DataSet obj obtaining
code: def encode(self, inputs):
      r"""
      NER evaluator for data preprocess
      :param list[Sample] data_samples: list of Samples
      :return: DataSet obj obtaining
  
      """
      word_seq = []
      tag_seq = []
      seq_len = []
      for sample in inputs:
          word_seq.append(sample["x"])
          tag_seq.append(sample["y"])
          seq_len.append(len(sample["x"]))
      return word_seq, tag_seq, seq_len
  
file_path: textflint/textflint/input/model/flint_model/flint_model_ner.py
imports: import json
  from ..metrics.nerspanmetric import NERSpanMetric
  from .flint_model import TASK_METRICS, FlintModel
  from ..test_model.bilstm_crf_torch import TaggerFactory
label_desc: Use image node_id 3 for calling the FlintModelNER obj's underlying member method code with example usage: obj.encode(inputs) and returns: word_seq,  tag_seq,  seq_len