code: function checkBreak(chr) {
    return (
      (B2.includes(chr) && 'B2') ||
      (BAI.includes(chr) && 'BAI') ||
      (SHY.includes(chr) && 'SHY') ||
      (BA.includes(chr) && 'BA') ||
      (BB.includes(chr) && 'BB') ||
      (BK.includes(chr) && 'BK')
    );
  }
docs: Check breaking character
  http://www.unicode.org/reports/tr14/#Table1
  
  @param chr