code: @PublicEvolving
  	public List<FlatFieldDescriptor> getFlatFields(String fieldExpression) {
  		List<FlatFieldDescriptor> result = new ArrayList<FlatFieldDescriptor>();
  		this.getFlatFields(fieldExpression, 0, result);
  		return result;
  	}
docs: Returns the flat field descriptors for the given field expression.
  
  @param fieldExpression The field expression for which the flat field descriptors are computed.
  @return The list of descriptors for the flat fields which are specified by the field expression.