private String responseToString(Response response) {
        return response == null ? "empty" : (String) response.getEntity();
    }
A general method that executes an HTTP request on a given URL.

@param url the HTTP endpoint
@param body the payload of the request; null if there isn't one
@param headers a map that stores the request headers; empty if there are no headers
@param httpMethod the name of the HTTP method to execute
@return the response to the HTTP request
@throws ConnectException if execution of the HTTP method fails
connect/runtime/src/test/java/org/apache/kafka/connect/util/clusters/EmbeddedConnect.java