text: import React from 'react';
  import PropTypes from 'prop-types';
  import './App.css';
  
  function App() {
    return (
      <Greeting person={{ name: "Some one", location: "Somewhere" }} />
    );
  }
  
  export default App;
  
  class Greeting extends React.Component {
    render() {
      return <p>Hello {this.props.person.name} in {this.props.person.location}</p>
    }
  }
  
  Greeting.propTypes = {
    person: PropTypes.shape({
      name: PropTypes.string.isRequired,
      location: PropTypes.string
    })
  }
  
  Greeting.defaultProps = {
    person: {
      name: "Unknown User",
      location: "Nowhere"
    }
  }