public void setContentMd5(String contentMd5) {
        this.contentMd5 = contentMd5;
    }
Sets the Base64-encoded MD5 hash of the object content that was
calculated on the client-side.

@param contentMd5
           The content MD5
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/PutObjectResult.java