add_border() {
    local -n _pic="$1"
    local -n _outPic="$2"
    local _width=${#_pic[0]}
    local _border
    _border=$(printf '%*s' "$_width" '' | tr ' ' '*')
    _outPic=("$_border")
    local _line
    for _line in "${_pic[@]}"; do
        _outPic+=("*${_line}*")
    done
    _outPic+=("$_border")
}