code: private static <T> StringBuilder appendAllTo(final StringBuilder buf, final String sep, final T... types) {
          Assert.requireNonNullEntries(types, "types");
          Assert.requireNotEmpty(types, "types");
          if (types.length > 0) {
              buf.append(toString(types[0]));
              for (int i = 1; i < types.length; i++) {
                  buf.append(sep).append(toString(types[i]));
              }
          }
          return buf;
      }
docs: Append {@code types} to {@code buf} with separator {@code sep}.
  
  @param buf   destination
  @param sep   separator
  @param types to append
  @return {@code buf}
  @since 3.2