code: public static Schema superSetOf(Schema schema, Field... newFields) {
  		return superSetOf("superSetSchema" + (COUNTER++), schema, newFields);
  	}
docs: Creates a superset of the input Schema, taking all the Fields in the input schema
  and adding some new ones. The new fields are fully specified in a Field class.
  The name of the schema is auto-generated with a static counter.