public void setStemming(Stemming value) {
        verifyThat((defaultStemming == null) || (defaultStemming == value),
                   "already has stemming", defaultStemming, "cannot also set", value);
        defaultStemming = value;
    }
This class holds the extracted information after parsing
one schema (.sd) file, using simple data structures
as far as possible.

Do not put complicated logic here!

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