radio-blog-7.js

class RadioGroup extends React.Component {
   render() {
      return this.props.children({
         name: this.props.name,
         onChange: this.handleChange
      });
   }
}

class UIComponent extends React.Component {
  handleChange = event => {};

  render() {
    return (
      <RadioGroup
        name="size"
        value={this.props.tshirt.value}
        onChange={this.handleChange}
      >
        {({ name, onChange }) => (
          <React.Fragment>
            <RadioOption value="m" name={name} onChange={onChange}>
              M
            </RadioOption>
            {/* two more of these with the respective props */}
          </React.Fragment>
        )}
      </RadioGroup>
    );
  }
}