class MyZone extends React.Component {
  onDrop = files => {
    this.setState({
      files: files.map(file => ({
        ...file,
        preview: URL.createObjectURL(file)
      }))
    });
  }

  cleanup = () => {
    // Revoke data uris when done using the previews
    const {files} = this.state;

    for (const file of files) {
      URL.revokeObjectURL(file.preview);
    }
  }

  render() {
    return (
      <Dropzone onDrop={this.onDrop} />
    );
  }
}