### Question:
Epsilon extends ERE { @Override public ERE copy() { return this; } private  Epsilon(); static Epsilon get(); @Override EREType getEREType(); @Override boolean equals(Object o); @Override int compareTo(Object o); @Override ERE copy(); @Override String toString(); @Override boolean containsEpsilon(); @Override ERE derive(Symbol s);  }### Answer:
@Test public void testCopy() { ERE copy = epsilon.copy(); assertEquals(epsilon, copy); }