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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 _get_classpath(self, workunit_factory):
 """Returns the bootstrapped ivy classpath as a list of jar paths. :raises: Bootstrapper.Error if the classpath could not be bootstrapped """

    if not self._classpath:
      self._classpath = self._bootstrap_ivy_classpath(workunit_factory)
    return self._classpath