code: def get_transaction_by_id(cls, txid):
          
  
          for api_call in cls.GET_TRANSACTION_BY_ID_MAIN:
              try:
                  return api_call(txid)
              except cls.IGNORED_ERRORS:
                  pass
  
          raise ConnectionError('All APIs are unreachable.')
docs: Gets a raw transaction hex by its transaction id (txid).
  
          :param txid: The id of the transaction
          :type txid: ``str``
          :raises ConnectionError: If all API services fail.
          :rtype: ``string``