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

        String searchName = schema.getName();
        Map<String, DataType> seenFields = new HashMap<>();
        verifySearchAndDocFields(searchName, seenFields);
        verifySummaryFields(searchName, seenFields);
    }
This Processor makes sure all fields with the same name have the same {@link DataType}. This check
explicitly disregards whether a field is an index field, an attribute or a summary field. This is a requirement if we
hope to move to a model where index fields, attributes and summary fields share a common field class.

@author Simon Thoresen Hult
config-model/src/main/java/com/yahoo/schema/processing/ValidateFieldTypes.java