public Optional<String> getResponseTemplate(String mimeType) {
        return Optional.ofNullable(responseTemplates.get(mimeType));
    }
Gets a specific response template by MIME type.

@param mimeType Response template MIME type.
@return Returns the optionally found response template.
smithy-aws-apigateway-traits/src/main/java/software/amazon/smithy/aws/apigateway/traits/IntegrationResponse.java