def replace(name, content=nil, &block)
      content = capture(&block) if block_given?
      add_instruction_to_area name, :replace, [content]
    end
def replace(name, content=nil, &block)
      content = capture(&block) if block_given?
      add_instruction_to_area name, :replace, [content]
    end
Replaces the content of an area previously declared or modified in parent layout(s). You can
 provide the content using either a String, or a block.

 @example Replacing content with a String
     <% replace :sidebar, "New content." %>

 @example Replacing content with a block:
     <% replace :sidebar do %>
       New content.
     <% end %>

 @param [Symbol] name
   A name to identify the area of content you wish to replace

 @param [String] content
   Optionally provide a String of content, instead of a block. A block will take precedence.