code: public static String unicodeEscaped(final Character ch) {
          if (ch == null) {
              return null;
          }
          return unicodeEscaped(ch.charValue());
      }
docs: <p>Converts the string to the Unicode format '\u0020'.</p>
  
  <p>This format is the Java source code format.</p>
  
  <p>If {@code null} is passed in, {@code null} will be returned.</p>
  
  <pre>
  CharUtils.unicodeEscaped(null) = null
  CharUtils.unicodeEscaped(' ')  = "\u0020"
  CharUtils.unicodeEscaped('A')  = "\u0041"
  </pre>
  
  @param ch  the character to convert, may be null
  @return the escaped Unicode string, null if null input