public StoreKey getStoreKey() {
    return key;
  }
Construct an instance of MessageInfo.
@param key the {@link StoreKey} associated with this message.
@param size the size of this message in bytes.
@param deleted {@code true} if the message is deleted, {@code false} otherwise
@param ttlUpdated {@code true} if the message's ttl has been updated, {@code false} otherwise
@param expirationTimeInMs the time at which the message will expire. A value of -1 means no expiration.
@param crc the crc associated with this message. If unavailable, pass in null.
@param accountId accountId of the blob
@param containerId containerId of the blob
@param operationTimeMs operation time in ms
@param lifeVersion update version of update
ambry-api/src/main/java/com/github/ambry/store/MessageInfo.java