### Question:
Atom extends LTLFormula { @Override public LTLFormula copy(){ return this; } private  Atom(); static Atom get(String name); @Override LTLType getLTLType(); @Override boolean equals(Object o); @Override int compareTo(Object o); @Override LTLFormula copy(); @Override String toString(); @Override void subFormulae(LinkedHashSet acc); @Override ATransition d(HashMap<LTLFormula, ATransition> D);  }### Answer:
@Test public void testCopy() { LTLFormula a_copy = a.copy(); assertEquals(a, a_copy); assertEquals(0, a.compareTo(a_copy)); assertEquals(a.hashCode(), a_copy.hashCode()); }