ker/mod/tfw.gestures.js
function getGesture( element_ ) {
    const element = ensureDom( element_ );
    if ( !element[ SYMBOL ] ) element[ SYMBOL ] = new Gesture( element );
    return element[ SYMBOL ];
}
function getGesture( element_ ) {
    const element = ensureDom( element_ );
    if ( !element[ SYMBOL ] ) element[ SYMBOL ] = new Gesture( element );
    return element[ SYMBOL ];
}
function getGesture ( element_ ) { const element = ensureDom ( element_ ) ; if ( ! element [ SYMBOL ] ) element [ SYMBOL ] = new Gesture ( element ) ; return element [ SYMBOL ] ; }
Return the associated gesture object. If it does not exist, create it.

@param   {[type]} element_ [description]
@returns {[type]}         [description]
Return the associated gesture object . If it does not exist create it .