http://localhost:8080/hawkular/metrics/gauges/MI~R~[snert~Local~/]~MT~WildFly Memory Metrics~Heap Max/data is apparrently not a valid Java.net.URI (which is the mother of the java.net.URL, at least syntax-definition-wise)

While [,],' ' can be encoded with %5b, %5d, %20 and so on, we should omit those characters that the URI format considers as "reserved"