class_docstr: Constructs a Pop2Piano tokenizer. This tokenizer does not require training.
  
  This tokenizer inherits from [`PreTrainedTokenizer`] which contains most of the main methods. Users should refer to
  this superclass for more information regarding those methods.
  
  Args:
      vocab (`str`):
          Path to the vocab file which contains the vocabulary.
      default_velocity (`int`, *optional*, defaults to 77):
          Determines the default velocity to be used while creating midi Notes.
      num_bars (`int`, *optional*, defaults to 2):
          Determines cutoff_time_idx in for each token.
docstr: Returns the vocabulary size of the tokenizer.
docstr_tok: ["Returns","the","vocabulary","size","of","the","tokenizer","."]
code: def vocab_size(self):
      """Returns the vocabulary size of the tokenizer."""
      return len(self.encoder)
  
imports: import json
  import os
  from typing import List, Optional, Tuple, Union
  import numpy
  from ...feature_extraction_utils import BatchFeature
  from ...tokenization_utils import AddedToken, BatchEncoding, PaddingStrategy, PreTrainedTokenizer, TruncationStrategy
  from ...utils import TensorType, is_pretty_midi_available, logging, requires_backends, to_numpy
label_desc: Use image node_id 2 for calling the Pop2PianoTokenizer obj's underlying member method code with example usage: obj.vocab_size() and returns: len