code: func (r *RuleDefault) IsWordSeparator(rune rune) bool {
  	chr := string(rune)
  
  	for _, val := range r.wordSeparators {
  		if chr == val {
  			return true
  		}
  	}
  
  	return r.IsSentenceSeparator(rune)
  }
docs: // IsWordSeparator method retrieves true when a character is a kind of special
  // character and possibly it separates to words from each other. It also checks
  // for sentence separator by IsSentenceSeparator method.