public void setProtocol(String protocol) {
        this.protocol = protocol;
    }
<p>
The protocol that was used for the DNS request.
</p>
<p>
Length Constraints: Minimum length of 1. Maximum length of 64.
</p>

@param protocol
       The protocol that was used for the DNS request.</p>
       <p>
       Length Constraints: Minimum length of 1. Maximum length of 64.
aws-java-sdk-securityhub/src/main/java/com/amazonaws/services/securityhub/model/DnsRequestAction.java