public Builder customAuthType(String customAuthType) {
            this.customAuthType = customAuthType;
            return this;
        }
Sets 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 "aws.v4", or "custom" otherwise.</p>

@param customAuthType the auth type (e.g. awsSigV4)
@return Returns the builder.
smithy-aws-apigateway-traits/src/main/java/software/amazon/smithy/aws/apigateway/traits/AuthorizerDefinition.java