{
  safe: (val) => (val != null ? '' + val : ''),
  workspaces_url: (base) => base + 'workspaces',
  models_url: (base, wid) => base + 'workspaces/' + wid + '/models',
  modules_url: (base, mid) => base + 'models/' + mid + '/modules',
  imports_url: (base, mid) => base + 'models/' + mid + '/imports',
  exports_url: (base, mid) => base + 'models/' + mid + '/exports',
  actions_url: (base, mid) => base + 'models/' + mid + '/actions',
  files_url: (base, mid) => base + 'models/' + mid + '/files',
  line_items_url: (base, mid, mod) => base + 'models/' + mid + '/modules/' + mod + '/lineItems',
  run_action_url: (base, mid, action_type, aid) => base + 'models/' + mid + '/' + action_type + '/' + aid + '/tasks',
  task_status_url: (base, mid, action_type, aid, tid) => base + 'models/' + mid + '/' + action_type + '/' + aid + '/tasks/' + tid,
  cell_data_url: (base, mid, mod) => base + 'models/' + mid + '/modules/' + mod + '/data'
}
