code: private void clearPrefOnBranchKeyChange() {
          // If stored key isn't the same as the current key, we need to clean up
          // Note: Link Click Identifier is not cleared because of the potential for that to mess up a deep link
          String linkClickID = getLinkClickID();
          String linkClickIdentifier = getLinkClickIdentifier();
          String appLink = getAppLink();
          String pushIdentifier = getPushIdentifier();
          prefsEditor_.clear();
          
          setLinkClickID(linkClickID);
          setLinkClickIdentifier(linkClickIdentifier);
          setAppLink(appLink);
          setPushIdentifier(pushIdentifier);
          prefHelper_.prefsEditor_.apply();
      }
docs: <p>Clears all the Branch referral shared preferences related to the current key.
  Should be called before setting an new Branch-Key. </p>