code: public static String getAbbreviatedName(final Class<?> cls, final int len) {
        if (cls == null) {
          return StringUtils.EMPTY;
        }
        return getAbbreviatedName(cls.getName(), len);
      }
docs: <p>Gets the abbreviated name of a {@code Class}.</p>
  
  @param cls  the class to get the abbreviated name for, may be {@code null}
  @param len  the desired length of the abbreviated name
  @return the abbreviated name or an empty string
  @throws IllegalArgumentException if len &lt;= 0
  @see #getAbbreviatedName(String, int)
  @since 3.4