public void setSizeInBytes(FileSystemSize sizeInBytes) {
        this.sizeInBytes = sizeInBytes;
    }
<p>
The latest known metered size (in bytes) of data stored in the file system, in its <code>Value</code> field, and
the time at which that size was determined in its <code>Timestamp</code> field. The <code>Timestamp</code> value
is the integer number of seconds since 1970-01-01T00:00:00Z. The <code>SizeInBytes</code> value doesn't represent
the size of a consistent snapshot of the file system, but it is eventually consistent when there are no writes to
the file system. That is, <code>SizeInBytes</code> represents actual size only if the file system is not modified
for a period longer than a couple of hours. Otherwise, the value is not the exact size that the file system was
at any point in time.
</p>

@param sizeInBytes
       The latest known metered size (in bytes) of data stored in the file system, in its <code>Value</code>
       field, and the time at which that size was determined in its <code>Timestamp</code> field. The
       <code>Timestamp</code> value is the integer number of seconds since 1970-01-01T00:00:00Z. The
       <code>SizeInBytes</code> value doesn't represent the size of a consistent snapshot of the file system, but
       it is eventually consistent when there are no writes to the file system. That is, <code>SizeInBytes</code>
       represents actual size only if the file system is not modified for a period longer than a couple of hours.
       Otherwise, the value is not the exact size that the file system was at any point in time.
aws-java-sdk-efs/src/main/java/com/amazonaws/services/elasticfilesystem/model/UpdateFileSystemResult.java