def add_tag(tag_name, timeout)
      cmd = { :name => :add_tag, :tag => tag_name }
      response = blocking_request(cmd, timeout)
      result = OperationResult.from_results(load(response, "Unexpected response #{response.inspect}"))
      if result.success?
        ::Chef::Log.info("Successfully added tag #{tag_name}")
      else
        raise TagError.new("Add tag failed: #{result.content}")
      end
      true
    end
def add_tag(tag_name, timeout)
      cmd = { :name => :add_tag, :tag => tag_name }
      response = blocking_request(cmd, timeout)
      result = OperationResult.from_results(load(response, "Unexpected response #{response.inspect}"))
      if result.success?
        ::Chef::Log.info("Successfully added tag #{tag_name}")
      else
        raise TagError.new("Add tag failed: #{result.content}")
      end
      true
    end
Add given tag to tags exposed by corresponding server

 === Parameters
 tag(String):: Tag to be added
 timeout(Fixnum):: Number of seconds to wait for agent response

 === Return
 true:: Always return true