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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 swap(self, i, j):
 		"""Swap the values at indices i & j. 		.. versionadded:: 1.1 		"""

		i = self._fix_neg_index(i)
		j = self._fix_neg_index(j)
		self._list[i], self._list[j] = self._list[j], self._list[i]
		self._dict[self._list[i]] = i
		self._dict[self._list[j]] = j