_getLeftAndRightPartAroundTheSelection() {
        const value = AutoNumericHelper.getElementValue(this.domElement);
        const left = value.substring(0, this.selection.start);
        const right = value.substring(this.selection.end, value.length);

        return [left, right];
    }
Return an array containing the string parts located on the left and right side of the caret or selection.
Those parts are left 'untouched', i.e. formatted by autoNumeric.

@returns {[string, string]} The parts on the left and right of the caret or selection
@private