How to use the @azure/amqp-common.Constants.partitionKey function in @azure/amqp-common

if (msg.timeToLive != null && msg.timeToLive !== Constants.maxDurationValue) {
    amqpMsg.ttl = msg.timeToLive;
    amqpMsg.creation_time = Date.now();
    if (Constants.maxAbsoluteExpiryTime - amqpMsg.creation_time > amqpMsg.ttl) {
      amqpMsg.absolute_expiry_time = amqpMsg.creation_time + amqpMsg.ttl;
    } else {
      amqpMsg.absolute_expiry_time = Constants.maxAbsoluteExpiryTime;
    }
  }
  if (msg.partitionKey != null) {
    if (msg.partitionKey.length > Constants.maxPartitionKeyLength) {
      throw new Error(
        "Length of 'partitionKey' property on the message cannot be greater than 128 characters."
      );
    }
    amqpMsg.message_annotations![Constants.partitionKey] = msg.partitionKey;
  }
  if (msg.viaPartitionKey != null) {
    if (msg.viaPartitionKey.length > Constants.maxPartitionKeyLength) {
      throw new Error(
        "Length of 'viaPartitionKey' property on the message cannot be greater than 128 characters."
      );
    }
    amqpMsg.message_annotations![Constants.viaPartitionKey] = msg.viaPartitionKey;
  }
  if (msg.scheduledEnqueueTimeUtc != null) {
    amqpMsg.message_annotations![Constants.scheduledEnqueueTime] = msg.scheduledEnqueueTimeUtc;
  }
  log.message("SBMessage to AmqpMessage: %O", amqpMsg);
  return amqpMsg;
}

if (msg.subject != null) {
    sbmsg.label = msg.subject;
  }
  if (msg.message_id != null) {
    sbmsg.messageId = msg.message_id;
  }
  if (msg.correlation_id != null) {
    sbmsg.correlationId = msg.correlation_id;
  }
  if (msg.reply_to_group_id != null) {
    sbmsg.replyToSessionId = msg.reply_to_group_id;
  }

  if (msg.message_annotations != null) {
    if (msg.message_annotations[Constants.partitionKey] != null) {
      sbmsg.partitionKey = msg.message_annotations[Constants.partitionKey];
    }
    if (msg.message_annotations[Constants.viaPartitionKey] != null) {
      sbmsg.viaPartitionKey = msg.message_annotations[Constants.viaPartitionKey];
    }
    if (msg.message_annotations[Constants.scheduledEnqueueTime] != null) {
      sbmsg.scheduledEnqueueTimeUtc = msg.message_annotations[Constants.scheduledEnqueueTime];
    }
  }

  const props: any = {};
  if (msg.message_annotations != null) {
    if (msg.message_annotations[Constants.deadLetterSource] != null) {
      props.deadLetterSource = msg.message_annotations[Constants.deadLetterSource];
    }
    if (msg.message_annotations[Constants.enqueueSequenceNumber] != null) {
      props.enqueuedSequenceNumber = msg.message_annotations[Constants.enqueueSequenceNumber];

if (msg.subject != null) {
    sbmsg.label = msg.subject;
  }
  if (msg.message_id != null) {
    sbmsg.messageId = msg.message_id;
  }
  if (msg.correlation_id != null) {
    sbmsg.correlationId = msg.correlation_id;
  }
  if (msg.reply_to_group_id != null) {
    sbmsg.replyToSessionId = msg.reply_to_group_id;
  }

  if (msg.message_annotations != null) {
    if (msg.message_annotations[Constants.partitionKey] != null) {
      sbmsg.partitionKey = msg.message_annotations[Constants.partitionKey];
    }
    if (msg.message_annotations[Constants.viaPartitionKey] != null) {
      sbmsg.viaPartitionKey = msg.message_annotations[Constants.viaPartitionKey];
    }
    if (msg.message_annotations[Constants.scheduledEnqueueTime] != null) {
      sbmsg.scheduledEnqueueTimeUtc = msg.message_annotations[Constants.scheduledEnqueueTime];
    }
  }

  const props: any = {};
  if (msg.message_annotations != null) {
    if (msg.message_annotations[Constants.deadLetterSource] != null) {
      props.deadLetterSource = msg.message_annotations[Constants.deadLetterSource];
    }
    if (msg.message_annotations[Constants.enqueueSequenceNumber] != null) {
      props.enqueuedSequenceNumber = msg.message_annotations[Constants.enqueueSequenceNumber];

}
  if (msg.subject != null) {
    sbmsg.label = msg.subject;
  }
  if (msg.message_id != null) {
    sbmsg.messageId = msg.message_id;
  }
  if (msg.correlation_id != null) {
    sbmsg.correlationId = msg.correlation_id;
  }
  if (msg.reply_to_group_id != null) {
    sbmsg.replyToSessionId = msg.reply_to_group_id;
  }

  if (msg.message_annotations != null) {
    if (msg.message_annotations[Constants.partitionKey] != null) {
      sbmsg.partitionKey = msg.message_annotations[Constants.partitionKey];
    }
    if (msg.message_annotations[Constants.viaPartitionKey] != null) {
      sbmsg.viaPartitionKey = msg.message_annotations[Constants.viaPartitionKey];
    }
    if (msg.message_annotations[Constants.scheduledEnqueueTime] != null) {
      sbmsg.scheduledEnqueueTimeUtc = msg.message_annotations[Constants.scheduledEnqueueTime];
    }
  }

  const props: any = {};
  if (msg.message_annotations != null) {
    if (msg.message_annotations[Constants.deadLetterSource] != null) {
      props.deadLetterSource = msg.message_annotations[Constants.deadLetterSource];
    }
    if (msg.message_annotations[Constants.enqueueSequenceNumber] != null) {