public void addInput(Reference name, RankProfile.Input input) {
        verifyThat(! inputs.containsKey(name), "already has input", name);
        inputs.put(name, input);
    }
This class holds the extracted information after parsing a
rank-profile block in a schema (.sd) file, using simple data
structures as far as possible.  Do not put advanced logic here!

@author arnej27959
config-model/src/main/java/com/yahoo/schema/parser/ParsedRankProfile.java