constructor ({
    database,
    routers,
    readers,
    writers,
    expirationTime,
    ttl
  } = {}) {
    this.database = database || null
    this.databaseName = database || 'default database'
    this.routers = routers || []
    this.readers = readers || []
    this.writers = writers || []
    this.expirationTime = expirationTime || int(0)
    this.ttl = ttl
  }
The routing table object used to determine the role of the servers in the driver.