public String toString() {
            return "(" + providerName + ":" + (path != null ? path + ":" : "") + variable + ")";
        }
Transforms the given configuration data by using the {@link ConfigProvider} instances to
look up values to replace the variables in the pattern.

@param configs the configuration values to be transformed
@return an instance of {@link ConfigTransformerResult}
clients/src/main/java/org/apache/kafka/common/config/ConfigTransformer.java