from prompt_toolkit.keys import Keys
from prompt_toolkit.completion import WordCompleter

@events.on_ptk_create
def outout_keybindings(prompter, history, completer, bindings, **kw):
    handler = bindings.add

    @handler('escape', 'u')  # actually alt+u
    def browse_links_handler(event):
        compl = WordCompleter(['selection1','selection2', 'selection3', 'selection4'])
        usr_sel = prompter.prompt('Enter your selection (TAB-complete): ',  completer=compl)
        my_process_selection(usr_sel)