code: public void put(final T key, final T val) {
      try (Txn<T> txn = env.txnWrite()) {
        put(txn, key, val);
        txn.commit();
      }
    }
docs: Starts a new read-write transaction and puts the key/data pair.
  
  @param key key to store in the database (not null)
  @param val value to store in the database (not null)
  @see #put(org.lmdbjava.Txn, java.lang.Object, java.lang.Object,
  org.lmdbjava.PutFlags...)