public GetObjectRequest withNonmatchingETagConstraint(String eTag) {
        this.nonmatchingEtagConstraints.add(eTag);
        return this;
    }
Sets a single ETag constraint to this request.
Returns this {@link GetObjectRequest}, enabling additional method
calls to be chained together.
<p>
Multiple ETag
constraints can be added to a request, but all ETag constraints <b>must
not</b> match the object's current ETag in order for this request to be
executed. If any entry in the non-matching ETag constraint list matches
the object's current ETag, this request <b>will not</b> be executed by
Amazon S3.
</p>

@param eTag
           The non-matching ETag constraint to add to this request.

@return This {@link GetObjectRequest}, enabling additional method
        calls to be chained together.

@see GetObjectRequest#getNonmatchingETagConstraints()
@see GetObjectRequest#setNonmatchingETagConstraints(List)
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/GetObjectRequest.java