docstr: Add a list of additional tokens to the encoder.
  The additional tokens are indexed starting from the last
  index of the
  current vocabulary in the order of the `special_tokens` list.
docstr_tok: ["Add","a","list","of","additional","tokens","to","the","encoder",".","The","additional","tokens","are","indexed","starting","from","the","last","index","of","the","current","vocabulary","in","the","order","of","the","`","special_tokens","`","list","."]
code: def add_special_tokens(self, special_tokens):
      """Add a list of additional tokens to the encoder.
      The additional tokens are indexed starting from the last
      index of the
      current vocabulary in the order of the `special_tokens` list.
      """
      if not special_tokens:
          self.special_tokens = {}
          self.special_tokens_decoder = {}
          return
      new = dict(
          (tok, self.code_column.vocab_size + i)
          for i, tok in enumerate(special_tokens)
          if tok not in self.special_tokens
      )
      self.special_tokens.update(new)
      self.special_tokens_decoder = {
          v: k for k, v in self.special_tokens.items()
      }
  
imports: import pickle
  from typing import List
  import numpy
  from nemo.collections.common.tokenizers.column_coder import ColumnCodes
  from nemo.collections.common.tokenizers.tokenizer_spec import TokenizerSpec
label_desc: Use image node_id 8 for calling the TabularTokenizer obj's underlying member method code with example usage: obj.add_special_tokens(special_tokens) without return types