@Override
    public void process(boolean validate, boolean documentsOnly) {
        if ( ! validate) return;

        if (schema.getDocument() == null)
            throw new IllegalArgumentException("For " + schema +
                                               ": A search specification must have an equally named document inside of it.");
    }
A search must have a document definition of the same name inside of it, otherwise crashes may occur as late as
during feeding

@author Vegard Havdal
config-model/src/main/java/com/yahoo/schema/processing/SearchMustHaveDocument.java