为什么PUT返回null？

Question

我不知道如何通过put方法的主体传递信息来更新GEM FAKER的薪水或年龄。如何在def update（id）方法中传递信息？ 我不知道如何通过put方法的主体传递信息来更新GEM FAKER的薪水或年龄。如何通过def update（id）方法传递信息？

require 'HTTParty'
require 'httparty/request'
require 'httparty/response/headers'
#require_relative '../hooks/hook'

class Crud

  include HTTParty
  base_uri 'http://dummy.restapiexample.com/api/v1'

  def create 
    nome = Faker::UniqueGenerator.clear
    nome = Faker::Name.unique.first_name
    salario = Faker::Number.decimal(l_digits: 4, r_digits: 2)
    idade   = Faker::Number.number(digits: 2)
    body = {name: nome, salary: salario, age: idade }.to_json

    headers = {
      'Accept' => 'application/vnd.tasksmanager.v2',
      'Content-Type' => 'application/json'
    }

    self.class.post('/create', body: body, headers: headers) 
  end

  def retrieve(id)
    self.class.get("/employee/#{ id }")
  end 

  def delete(id)
    self.class.delete("/delete/#{ id }")
  end

  def update(id)
    self.class.put("/update/#{ id }")
  end
end

@response = $manter_user.create
expect(@response.code).to eq (200)
puts @response.body
@id = JSON.parse(@response['salary')                                                                                                                                                   
puts $manter_ser.update(@id)

{"name":"Devon","salary":"3901.29","age":"10","id":"184573"}
{"name":null,"salary":null,"age":null}