code: func HasPattern(pattern string) bool {
  	for i := 0; i < len(pattern); i++ {
  		switch pattern[i] {
  		case '\\':
  			i++
  		case '*', '?', '[':
  			return true
  		}
  	}
  	return false
  }
docs: // HasPattern returns whether a string contains any unescaped wildcard
  // characters: '*', '?', or '['. When the function returns false, the given
  // pattern can only match at most one string.
  //
  // For example, HasPattern(`foo\*bar`) returns false, but HasPattern(`foo*bar`)
  // returns true.
  //
  // This can be useful to avoid extra work, like TranslatePattern. Note that this
  // function cannot be used to avoid QuotePattern, as backslashes are quoted by
  // that function but ignored here.