digraph G {
 rankdir=TB
 node [shape=box, fontsize=9, height=0.1, width=0.05 ]
 edge [arrowsize=0.5, len=0.1]
"VacationDays\n"->"age\nservice\ndays\n"
"age\nservice\ndays\n"->"age\nservice\n"
"age\nservice\ndays\n"->"days\n"
"age\nservice\n"->"age\n"
"age\nservice\n"->"service\n"
}