The java code is correct but the checks do not work as you can see. Please help me solve the issue. Please help only if you can I don't want to waste the question.

Modiy the Class FormLetterWriter that includes two overloaded methods named displaySalutation(). The first method takes one String parameter that represents a customer's last name, and it displays the salutation Dear Mr. or Ms. followed by the last name. The second method accepts two String parameters that represent a first and last name, and it displays the greeting Dear followed by the first name, a space, and the last name. After each salutation, display the rest of a short business letter using the displayLetter method: Thank you for your recent order. An example of the program is shown below: Tasks O out of 4 checks passed. Review the results below for more details. Checks Unit Test Incomplete displaySalutation("John") 1 public class FormLetterWriter { 2 3 public static void main(String[] args) { 4 displaySalutation ("Kelly"); 5 displayLetter(); 6 displaySalutation ("Christy", "Johnson"); 7 displayLetter(); 8 } 9 10 public static void displaySalutation(String lastName) { 11 System.out.println("Dear Mr. or Ms. " + lastName); 12 } 13 14 public static void displaySalutation(String firstName, String lastName) { 15 System.out.println("Dear " + firstName + + lastName); 16 } 17 18 public static void display Letter() { 19 System.out.println("Thank you for your recent order."); 20 } 21 } 22 > Unit Test Incomplete displaySalutation ("Maria") > Unit Test Incomplete displaySalutation("Greta", "Gerwig") > Unit Test . Incomplete displaySalutation("Hayao", "Miyazaki")