code: func (options *Options) isIncludableZero() bool {
  	b, ok := options.HashProp("includeZero").(bool)
  	if ok && b {
  		nb, ok := options.Param(0).(int)
  		if ok && nb == 0 {
  			return true
  		}
  	}
  
  	return false
  }
docs: //
  // Misc
  //
  // isIncludableZero returns true if 'includeZero' option is set and first param is the number 0