function doesImageExist(file, imgPath, node) {
  const msgHardCoded = 'Do not hard code `developers.google.com` in paths.';
  // Is the image potentially on a remote server?
  //  - indicated by http:// or https://
  if (reRemote.test(imgPath)) {
    // Is it on our server?
    if (imgPath.indexOf('developers.google.com') > 0) {
      file.message(msgHardCoded, node);
      imgPath = imgPath.replace(/https?:\/\/developers\.google\.com/i, '');
    } else {
      return;
    }
  }
  let filePath = file.cwd;
  if (imgPath.indexOf('/') === 0) {
    const noWeb = imgPath.replace('/web/', '');
    filePath = path.join(filePath, 'src/content/en', noWeb);
  } else {
    filePath = path.join(filePath, file.dirname, imgPath);
  }
  try {
    fs.accessSync(filePath, fs.R_OK);
    return true;
  } catch (ex) {
    let msg = `Unable to find image \`${imgPath}\``;
    file.message(msg, node);
  }
}
Verifies that images exist and links are properly used.

@param {Object} file The source file that included the image
@param {Object} imgPath The URI to the image
@param {Object} node The Remark node
@return {null} Nothing