code: public void addTupleInput(Path path, Schema targetSchema, TupleMapper<ITuple, NullWritable> tupleMapper) {
  		addInput(path, new TupleInputFormat(targetSchema), tupleMapper);
  	}
docs: Adds an input file associated with a TupleFile.
  <p>
  A specific "Target Schema" is specified, which should be backwards-compatible with the Schema in the
  Tuple File (new nullable fields are allowed, not used old fields too).