code: public static String toMultiRowString(Collection<?> collection) {
          if (collection == null) {
              return null;
          }
          if (collection.isEmpty()) {
              return "(empty collection)";
          }
          StringBuilder builder = new StringBuilder("\n  - ");
          for (Iterator<?> iterator = collection.iterator(); iterator.hasNext();) {
              builder.append(iterator.next());
              if (iterator.hasNext()) {
                  builder.append(",\n  - ");
              }
          }
          return builder.toString();
      }
docs: Returns the supplied collection as a multi-row string with every toString() of every element of the collection
  in its own row.
  Example: toMultiRowString(Arrays.asList("aaa", "bbb", "ccc")) will return:
  <pre>
  - aaa,
  - bbb,
  - ccc
  </pre>