public String getFirstSnapshotId() {
        return this.firstSnapshotId;
    }
<p>
The ID of the first snapshot to use for the comparison.
</p>
<important>
<p>
The <code>FirstSnapshotID</code> parameter must be specified with a <code>SecondSnapshotId</code> parameter;
otherwise, an error occurs.
</p>
</important>

@return The ID of the first snapshot to use for the comparison.</p> <important>
        <p>
        The <code>FirstSnapshotID</code> parameter must be specified with a <code>SecondSnapshotId</code>
        parameter; otherwise, an error occurs.
        </p>
aws-java-sdk-ebs/src/main/java/com/amazonaws/services/ebs/model/ListChangedBlocksRequest.java