static DocServiceFilter ofRegex(Pattern pattern) {
        requireNonNull(pattern, "pattern");
        return (plugin, service, method) -> {
            final String concatenatedName = plugin + ':' + service + '#' + method;
            return pattern.matcher(concatenatedName).find();
        };
    }
Returns a {@link DocServiceFilter} which returns {@code true} when the concatenated name of the plugin,
service and method matches the specified {@link Pattern}.
The concatenated name will be {@code "pluginName + ':' + serviceName + '#' + methodName"}. For example:
<pre>{@code
grpc:armeria.grpc.FooService#EmptyCall // gRPC.
thrift:com.linecorp.armeria.service.thrift.BarService#myMethod // Thrift.
annotated:com.linecorp.armeria.annotated.BazService#myMethod // Annotated service.
}</pre>
core/src/main/java/com/linecorp/armeria/server/docs/DocServiceFilter.java