code: def alias(self, person, identity, path=KISSmetrics.ALIAS_PATH):
          
          this_request = request.alias(self.key, person, identity,
                                       scheme=self.trk_scheme,
                                       host=self.trk_host, path=path)
          return self._request(this_request)
docs: Map `person` to `identity`; actions done by one resolve to other.
  
          :param person: consider as same individual ``identity``; the
                         source of the alias operation
          :type person: str or unicode
          :param identity: consider as an alias of ``person``; the target
                           of the alias operation
          :type identity: str or unicode
          :param path: HTTP endpoint to use; defaults to
                      ``KISSmetrics.ALIAS_PATH``
  
          :returns: an HTTP response for the request
          :rtype: `urllib3.response.HTTPResponse`
  
          Note the direction of the mapping is ``person`` to ``identity``
          (so "``person`` is also known as ``identity``" or "``person`` =>
          ``identity``" when looking at it as "``<source>`` => ``<target>``")
  
          When consulting the Aliasing documentation, `person` corresponds
          to ``query_string.PERSON_PARAM`` and `identity` corresponds to
          ``query_string.ALIAS_PARAM``.
  
          Aliasing is not a reversible operation.  When aliasing to an
          identity, take care not to use a session identifier or any other
          value that is not relatively stable (a value that will not
          change per request or per session).
  
          For more information see the API Specifications on `Aliasing
          <http://support.kissmetrics.com/apis/specifications.html#aliasing-users>`_.