public String getAvailabilityZoneId() {
        return this.availabilityZoneId;
    }
<p>
The unique and consistent identifier of the Availability Zone in which the file system is located, and is valid
only for One Zone file systems. For example, <code>use1-az1</code> is an Availability Zone ID for the us-east-1
Amazon Web Services Region, and it has the same location in every Amazon Web Services account.
</p>

@return The unique and consistent identifier of the Availability Zone in which the file system is located, and is
        valid only for One Zone file systems. For example, <code>use1-az1</code> is an Availability Zone ID for
        the us-east-1 Amazon Web Services Region, and it has the same location in every Amazon Web Services
        account.
aws-java-sdk-efs/src/main/java/com/amazonaws/services/elasticfilesystem/model/UpdateFileSystemResult.java