TrieEntry implements Entry<String, T> { @Override public String toString() { return key + "=" + value; } TrieEntry(char character, @Nullable TrieEntry<T> parent);   TrieEntry(char character, @Nullable TrieEntry<T> parent, String key, T value); @Override @Nullable String getKey(); @Override @Nullable T getValue(); @Override @Nullable T setValue(T value); @Override boolean equals(Object other); @Override int hashCode(); @Override String toString();  }
@Test void to_string() { assertEquals("e=mc2", new TrieEntry<>(' ', null, "e", "mc2").toString()); }