code: func (styleRule *StyleRule) String() string {
  	result := ""
  
  	result += styleRule.Selector
  
  	if len(styleRule.Declarations) == 0 {
  		result += ";"
  	} else {
  		result += " {\n"
  
  		for _, decl := range styleRule.Declarations {
  			result += fmt.Sprintf("  %s\n", decl.String())
  		}
  
  		result += "}"
  	}
  
  	return result
  }
docs: // Returns the string representation of a style rule