parameters: (self, src_vocab: VocabEntry, tgt_vocab: VocabEntry)
docstring: Init Vocab.
          @param src_vocab (VocabEntry): VocabEntry for source language
          @param tgt_vocab (VocabEntry): VocabEntry for target language
docstring_summary: Init Vocab.
docstring_tokens: Init Vocab .
function: def __init__(self, src_vocab: VocabEntry, tgt_vocab: VocabEntry):
          """ Init Vocab.
          @param src_vocab (VocabEntry): VocabEntry for source language
          @param tgt_vocab (VocabEntry): VocabEntry for target language
          """
          self.src = src_vocab
          self.tgt = tgt_vocab
function_tokens: def __init__ ( self , src_vocab : VocabEntry , tgt_vocab : VocabEntry ) : self . src = src_vocab self . tgt = tgt_vocab