docs: public HCatInputFormatBase<T> getFields(String... fields) throws IOException {
  
  		// build output schema
  		ArrayList<HCatFieldSchema> fieldSchemas = new ArrayList<HCatFieldSchema>(fields.length);
  		for (String field : fields) {
  			fieldSchemas.add(this.outputSchema.get(field));
  		}
  		this.outputSchema = new HCatSchema(fieldSchemas);
  
  		// update output schema configuration
  		configuration.set("mapreduce.lib.hcat.output.schema", HCatUtil.serialize(outputSchema));
  
  		return this;
  	}