public void setExpectedRevisionId(String expectedRevisionId) {
        this.expectedRevisionId = expectedRevisionId;
    }
<p>
The identifier of the revision of the policy to edit. If this revision ID doesn't match the current revision ID,
Amazon Lex throws an exception.
</p>
<p>
If you don't specify a revision, Amazon Lex overwrites the contents of the policy with the new values.
</p>

@param expectedRevisionId
       The identifier of the revision of the policy to edit. If this revision ID doesn't match the current
       revision ID, Amazon Lex throws an exception.</p>
       <p>
       If you don't specify a revision, Amazon Lex overwrites the contents of the policy with the new values.
aws-java-sdk-lexmodelsv2/src/main/java/com/amazonaws/services/lexmodelsv2/model/CreateResourcePolicyStatementRequest.java