code: public static boolean isSpaceChar(int codePoint) {
          // We don't just call into icu4c because of the JNI overhead. Ideally we'd fix that.
          // SPACE or NO-BREAK SPACE?
          if (codePoint == 0x20 || codePoint == 0xa0) {
              return true;
          }
          if (codePoint < 0x1000) {
              return false;
          }
          // OGHAM SPACE MARK or MONGOLIAN VOWEL SEPARATOR?
          if (codePoint == 0x1680 || codePoint == 0x180e) {
              return true;
          }
          if (codePoint < 0x2000) {
              return false;
          }
          if (codePoint <= 0xffff) {
              // Other whitespace from General Punctuation...
              return codePoint <= 0x200a || codePoint == 0x2028 || codePoint == 0x2029 || codePoint == 0x202f || codePoint == 0x205f ||
                  codePoint == 0x3000; // ...or CJK Symbols and Punctuation?
          }
          // Let icu4c worry about non-BMP code points.
          return isSpaceCharImpl(codePoint);
      }
docs: Determines if the specified character (Unicode code point) is a
  Unicode space character.  A character is considered to be a
  space character if and only if it is specified to be a space
  character by the Unicode Standard. This method returns true if
  the character's general category type is any of the following:
  
  <ul>
  <li> {@link #SPACE_SEPARATOR}
  <li> {@link #LINE_SEPARATOR}
  <li> {@link #PARAGRAPH_SEPARATOR}
  </ul>
  
  @param   codePoint the character (Unicode code point) to be tested.
  @return  {@code true} if the character is a space character;
  {@code false} otherwise.
  @see     Character#isWhitespace(int)
  @since   1.5