def list_eval_keys(prefix=''):
  """List the keys of the dictionary returned by the evaluate function."""
  keys = [
      'EPE', 'ER', 'inf-time(ms)', 'eval-time(s)', 'occl-f-max',
      'best-occl-thresh'
  ]
  if prefix:
    return [prefix + '-' + k for k in keys]
  return keys