code: public String[] getSynonyms(String word) {
      String[] synonyms = table.get(word);
      if (synonyms == null) return EMPTY;
      String[] copy = new String[synonyms.length]; // copy for guaranteed immutability
      System.arraycopy(synonyms, 0, copy, 0, synonyms.length);
      return copy;
    }
docs: Returns the synonym set for the given word, sorted ascending.
  
  @param word
  the word to lookup (must be in lowercase).
  @return the synonyms; a set of zero or more words, sorted ascending, each
  word containing lowercase characters that satisfy
  <code>Character.isLetter()</code>.