public Optional<String> getCustomAuthType() {
        return Optional.ofNullable(customAuthType);
    }
Gets the customAuthType of the authorizer.

<p>This value is not used directly by APIGateway but will be used for
OpenAPI exports. This will default to "awsSigV4" if your scheme is
{@code aws.auth#sigv4}.

@return Returns the customAuthType.
smithy-aws-apigateway-traits/src/main/java/software/amazon/smithy/aws/apigateway/traits/AuthorizerDefinition.java