code: public void getFieldsIntoCheckingNull(int[] positions, Value[] targets) {
  		for (int i = 0; i < positions.length; i++) {
  			if (!getFieldInto(positions[i], targets[i])) {
  				throw new NullKeyFieldException(i);
  			}
  		}
  	}
docs: Gets the fields at the given positions into an array.
  If at any position a field is null, then this method throws a @link NullKeyFieldException.
  All fields that have been successfully read until the failing read are correctly contained in the record.
  All other fields are not set.
  
  @param positions The positions of the fields to get.
  @param targets The values into which the content of the fields is put.
  
  @throws NullKeyFieldException in case of a failing field read.