code: public static final int codePointAt(CharSequence seq, int index) {
          char c1 = seq.charAt(index++);
          if (isHighSurrogate(c1)) {
              if (index < seq.length()) {
                  char c2 = seq.charAt(index);
                  if (isLowSurrogate(c2)) {
                      return toCodePoint(c1, c2);
                  }
              }
          }
          return c1;
      }
docs: Same as {@link Character#codePointAt(CharSequence, int)}.
  Returns the code point at index.
  This examines only the characters at index and index+1.
  
  @param seq the characters to check
  @param index the index of the first or only char forming the code point
  @return the code point at the index