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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _encoder(self):
 """Transliterate a string from the input language to English."""

    if self.source_lang == 'en':
      return Transliterator._dummy_coder
    else:
      weights = load_transliteration_table(self.source_lang)
      encoder_weights = weights["encoder"]
      return Transliterator._transliterate_string(encoder_weights)