exports.activate = context => {

  const vscode = require('vscode');
  const red = window.createTextEditorDecorationType({
    isWholeLine: true,
    backgroundColor: 'red'
  });
  const green = window.createTextEditorDecorationType({
    isWholeLine: true,
    backgroundColor: 'green'
  });

  window.activeTextEditor.setDecorations(red, [new vscode.Range(0, 1, 0, 100)]);
  window.activeTextEditor.setDecorations(green, [new vscode.Range(1, 1, 1, 100)]);

  context.subscriptions.push({dispose: () => {
    window.activeTextEditor.setDecorations(red, []);
    window.activeTextEditor.setDecorations(green, []);
    red.dispose();
    green.dispose();
  }});
};