How to use the deltachat-node/constants.DC_STATE_OUT_MDN_RCVD function in deltachat-node

function mapCoreMsgStatus2String (state) {
  switch (state) {
    case C.DC_STATE_OUT_FAILED:
      return 'error'
    case C.DC_STATE_OUT_PENDING:
      return 'sending'
    case C.DC_STATE_OUT_PREPARING:
      return 'sending'
    case C.DC_STATE_OUT_DRAFT:
      return 'draft'
    case C.DC_STATE_OUT_DELIVERED:
      return 'delivered'
    case C.DC_STATE_OUT_MDN_RCVD:
      return 'read'
    default:
      return '' // to display no icon on unknown state
  }
}
function isGroupChat (chat) {

function mapCoreMsgStatus2String (state) {
  switch (state) {
    case C.DC_STATE_OUT_FAILED:
      return 'error'
    case C.DC_STATE_OUT_PENDING:
      return 'sending'
    case C.DC_STATE_OUT_PREPARING:
      return 'sending'
    case C.DC_STATE_OUT_DRAFT:
      return 'draft'
    case C.DC_STATE_OUT_DELIVERED:
      return 'delivered'
    case C.DC_STATE_OUT_MDN_RCVD:
      return 'read'
    case C.DC_STATE_IN_FRESH:
      return 'delivered'
    case C.DC_STATE_IN_SEEN:
      return 'delivered'
    case C.DC_STATE_IN_NOTICED:
      return 'read'
    default:
      return '' // to display no icon on unknown state
  }
}

function convertMessageStatus (s) {
  switch (s) {
    case CONSTANTS.DC_STATE_IN_FRESH:
      return 'sent'
    case CONSTANTS.DC_STATE_OUT_FAILED:
      return 'error'
    case CONSTANTS.DC_STATE_IN_SEEN:
      return 'read'
    case CONSTANTS.DC_STATE_IN_NOTICED:
      return 'read'
    case CONSTANTS.DC_STATE_OUT_DELIVERED:
      return 'delivered'
    case CONSTANTS.DC_STATE_OUT_MDN_RCVD:
      return 'read'
    case CONSTANTS.DC_STATE_OUT_PENDING:
      return 'sending'
    case CONSTANTS.DC_STATE_UNDEFINED:
      return 'error'
  }
}

function convertMessageStatus (s) {
  switch (s) {
    case C.DC_STATE_IN_FRESH:
      return 'sent'
    case C.DC_STATE_OUT_FAILED:
      return 'error'
    case C.DC_STATE_IN_SEEN:
      return 'read'
    case C.DC_STATE_IN_NOTICED:
      return 'read'
    case C.DC_STATE_OUT_DELIVERED:
      return 'delivered'
    case C.DC_STATE_OUT_MDN_RCVD:
      return 'read'
    case C.DC_STATE_OUT_PENDING:
      return 'sending'
    case C.DC_STATE_UNDEFINED:
      return 'error'
  }
}