Provide implementation for a MergeSort method, performed on an array of the attached Person class.

This method should sort Person objects alphabetically first by LastName, then FirstName, and then again by the Person BirthYear

c# $```$

namespace SearchSortAssignment

$\{$

public class Person

$\{$

public string FirstName $\{$ get; $\}$

public string LastName $\{$ get; $\}$

public int BirthYear $\{$ get; $\}$

public Person$($string firstName, string lastName, int birthYear$)$

$\{$

FirstName $=$ firstName;

LastName $=$ lastName;

BirthYear $=$ birthYear;

$\}$

$\}|$

$\}$

$```$