code: static String[] toNoNullStringArray(final Collection<String> collection) {
          if (collection == null) {
              return ArrayUtils.EMPTY_STRING_ARRAY;
          }
          return toNoNullStringArray(collection.toArray());
      }
docs: Converts the given Collection into an array of Strings. The returned array does not contain <code>null</code>
  entries. Note that {@link Arrays#sort(Object[])} will throw an {@link NullPointerException} if an array element
  is <code>null</code>.
  
  @param collection
  The collection to convert
  @return A new array of Strings.