add the test class

Author: dbc2201

pom.xml

@@ -7,6 +7,14 @@
     <groupId>io.github.dbc</groupId>
     <artifactId>JCP_C1_P1</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>5.8.2</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
 
     <properties>
         <maven.compiler.source>18</maven.compiler.source>

src/test/java/io/github/dbc/DuplicateCharactersCounterTest.java

@@ -0,0 +1,22 @@
+package io.github.dbc;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+class DuplicateCharactersCounterTest {
+
+    private DuplicateCharactersCounter counter;
+
+    @BeforeEach
+    void setUp() {
+        counter = new DuplicateCharactersCounter();
+    }
+
+    @Test
+    @DisplayName("")
+    void countDuplicateCharacters() {
+        Assertions.fail();
+    }
+}