Load ComboBox when write form WebService in V8

I have a problem with the ComboBox in Vaddin 8 (or 8.1).
I want to load a combobox (calling a WebService) when i write into the ComboBox.
In version 7 had no problems because it had the Listener TextChangeListener () and program there …
Anyone know how I can do it with Vaadin 8?
Thank you !!!

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