code: func mergeStyleDeclarations(styleRules []*StyleRule, output map[string]*StyleDeclaration) {
  	for _, styleRule := range styleRules {
  		for _, declaration := range styleRule.Declarations {
  			styleDecl := NewStyleDeclaration(styleRule, declaration)
  
  			if (output[declaration.Property] == nil) || (styleDecl.Specificity() >= output[declaration.Property].Specificity()) {
  				output[declaration.Property] = styleDecl
  			}
  		}
  	}
  }
docs: // helper