/// <summary>
/// Start processing person object from reading, parsing, validating, sorting, and writing to output file
/// </summary>
/// <param name="reader">person data provider</param>
/// <param name="parser">person data parser</param>
/// <param name="writer">person data writer</param>
/// <param name="validator">person data validator</param>
/// <param name="sorter">person data sorter</param>
/// <returns>List of persons</returns>
public IList <PersonDTO> Process()
{
Messages = new List <String>();
var providedData = _reader.Read();
var parsedData = _parser.Parse(providedData);
var validatedData = _validator.Validate(parsedData);
var sortedData = _sorter.Sort(validatedData);
_writer.Write(sortedData);
Messages = Messages.Concat(_validator.Messages);
return(sortedData);
}