def post_vrule(service_name = nil, section_name = nil, graph_name = nil, params = {})
      path = "/vrule/api"
      path += "/#{e service_name}" if service_name
      path += "/#{e section_name}" if section_name
      path += "/#{e graph_name}"   if graph_name
      post_query(path, params)
    end
def post_vrule(service_name = nil, section_name = nil, graph_name = nil, params = {})
      path = "/vrule/api"
      path += "/#{e service_name}" if service_name
      path += "/#{e section_name}" if section_name
      path += "/#{e graph_name}"   if graph_name
      post_query(path, params)
    end
Post parameters to a vrule, POST /vrule/api/:service_name/:section_name/:graph_name
 @param [String] service_name
 @param [String] section_name
 @param [String] graph_name
 @param [Hash] params The POST parameters. See #get_vrule
 @return [Hash] the error code and graph property
 @example
{"error"=>0,
"data"=>{
  "graph_path"=>"/hoge/hoge/hoge",
  "color"=>"#FF0000",
  "time"=>1395826210,
  "id"=>1,
  "dashes"=>"2,10",
  "description"=>""}}