@Override
    public void close(IAsyncResultHandler<Void> handler) {
        try {
            connection.close();
            handler.handle(AsyncResultImpl.create((Void) null, Void.class));
        } catch (SQLException e) {
            handler.handle(AsyncResultImpl.create(e, Void.class));
        }
    }
@see io.apiman.gateway.engine.components.jdbc.IJdbcConnection#close(io.apiman.gateway.engine.async.IAsyncResultHandler)
gateway/engine/core/src/main/java/io/apiman/gateway/engine/impl/DefaultJdbcConnection.java