code: public static X509CRLEntryImpl toImpl(X509CRLEntry entry)
              throws CRLException {
          if (entry instanceof X509CRLEntryImpl) {
              return (X509CRLEntryImpl)entry;
          } else {
              return new X509CRLEntryImpl(entry.getEncoded());
          }
      }
docs: Utility method to convert an arbitrary instance of X509CRLEntry
  to a X509CRLEntryImpl. Does a cast if possible, otherwise reparses
  the encoding.