public void setEmailSubject(String emailSubject) {
        this.emailSubject = emailSubject;
    }
<p>
The subject line for email messages. EmailSubject is allowed only if <a href=
"https://docs.aws.amazon.com/cognito-user-identity-pools/latest/APIReference/API_EmailConfigurationType.html#CognitoUserPools-Type-EmailConfigurationType-EmailSendingAccount"
>EmailSendingAccount</a> is DEVELOPER.
</p>

@param emailSubject
       The subject line for email messages. EmailSubject is allowed only if <a href=
       "https://docs.aws.amazon.com/cognito-user-identity-pools/latest/APIReference/API_EmailConfigurationType.html#CognitoUserPools-Type-EmailConfigurationType-EmailSendingAccount"
       >EmailSendingAccount</a> is DEVELOPER.
aws-java-sdk-cognitoidp/src/main/java/com/amazonaws/services/cognitoidp/model/MessageTemplateType.java