docs: function getProperty (service, resource, action, propertySpec) {
    const parts = propertySpec.split('.')
    var target
    switch (parts[ 0 ]) {
      case 'action':
        target = action
        break
      case 'resource':
        target = resource
        break
      default:
        target = service
    }
    const property = parts[ 1 ]
    return { key: property, value: target ? target[ property ] : null }
  }