text: """Define constant values used thoughout the project."""
  
  PADDING_TOKEN = "<blank>"
  START_OF_SENTENCE_TOKEN = "<s>"
  END_OF_SENTENCE_TOKEN = "</s>"
  UNKNOWN_TOKEN = "<unk>"
  MASK_TOKEN = "<mask>"
  
  PADDING_ID = 0
  START_OF_SENTENCE_ID = 1
  END_OF_SENTENCE_ID = 2
  MASK_TOKEN_ID = 3