如何在graphql-fhir中执行实例查询？

const { graphql, buildSchema } = require('graphql');
const { executeQuery } = require('graphql-fhir');

// 定义GraphQL Schema
const schema = buildSchema(`
  type Query {
    patient(id: ID!): Patient
  }

  type Patient {
    id: ID!
    name: String
    gender: String
    birthDate: String
  }
`);

// 定义Resolver
const root = {
  patient: ({ id }) => {
    // 执行实例查询
    const query = `
      {
        Patient(id: "${id}") {
          id
          name
          gender
          birthDate
        }
      }
    `;
    const result = executeQuery(query);

    // 返回查询结果
    return result.data.Patient;
  }
};

// 执行查询
const query = `
  query {
    patient(id: "123") {
      id
      name
      gender
      birthDate
    }
  }
`;

graphql(schema, query, root).then((result) => {
  console.log(result);
});