public Attribute getAttribute(String name) {
        for (ImmutableSDField field : allConcreteFields()) {
            Attribute attribute = field.getAttributes().get(name);
            if (attribute != null) {
                return attribute;
            }
        }
        return null;
    }
Returns the first occurrence of an attribute having this name, or null if none
config-model/src/main/java/com/yahoo/schema/Schema.java