### Question:
Vertex implements Serializable { public String shortenName(String name) { if (name == null) { return "null"; } return name; } protected  Vertex(String actor, String action, boolean isSpecial, String filePath,
                     List<Integer> lineNumbers, String location); boolean isLineNumbersEmpty(); String getActor(); String getAction(); boolean isSpecial(); String getFilePath(); List<Integer> getLineNumbers(); String getLocation(); void setLocation(String location); String shortenName(String name); @Override String toString(); @Override int hashCode(); @Override boolean equals(Object o);  }### Answer:
@Test public void testShortenName() { Vertex v = new Vertex.Builder("actor", "action").build(); assertEquals("name", v.shortenName("name")); assertEquals("null", v.shortenName(null)); }