code: @Nonnull
      public Word<I> prepend(@Nullable I symbol) {
          int len = length();
          Object[] array = new Object[len + 1];
          array[0] = symbol;
          writeToArray(0, array, 1, len);
  
          return new SharedWord<>(array);
      }
docs: Prepends a symbol to this word and returns the result as a new word.
  
  @param symbol
  the symbol to prepend
  
  @return the given symbol plus to word.