Add Unit tests "isValid" and update README

README.md

@@ -51,6 +51,11 @@ final CUID cuid = CUID.fromString("cl9gts1kw00393647w1z4v2tc");
 System.out.println("CUID: " + cuid);
 ```
 
+```java
+final boolean isValid = CUID.isValid("cl9gts1kw00393647w1z4v2tc");
+System.out.println("Is 'cl9gts1kw00393647w1z4v2tc' a valid CUID ? " + isValid);
+```
+
 
 ## License
 This project is released under terms of the [MIT license](https://raw.githubusercontent.com/thibaultmeyer/cuid-java/master/LICENSE).

src/main/java/io/github/thibaultmeyer/cuid/CUID.java

@@ -108,7 +108,7 @@ public static CUID fromString(final String cuidAsString) {
      * Checks the {@code CUID} from the string standard representation.
      *
      * @param cuidAsString A string that specifies a {@code CUID} (Version 1 or 2)
-     * @return {@code true} If the string is not conform, otherwise, {@code false}
+     * @return {@code true} If the string is conforms, otherwise, {@code false}
      * @since 1.0.0
      */
     public static boolean isValid(final String cuidAsString) {

src/test/java/io/github/thibaultmeyer/cuid/CUIDv1Test.java

@@ -42,6 +42,32 @@ void fromStringInvalid() {
         Assertions.assertEquals("CUID string is invalid: 'invalid-cuid'", exception.getMessage());
     }
 
+    @Test
+    void isValid() {
+
+        // Arrange
+        final String cuidAsString = "cl9gts1kw00393647w1z4v2tc";
+
+        // Act
+        final boolean isValid = CUID.isValid(cuidAsString);
+
+        // Assert
+        Assertions.assertTrue(isValid);
+    }
+
+    @Test
+    void isValidInvalid() {
+
+        // Arrange
+        final String cuidAsString = "not-a-cuid";
+
+        // Act
+        final boolean isValid = CUID.isValid(cuidAsString);
+
+        // Assert
+        Assertions.assertFalse(isValid);
+    }
+
     @Test
     void randomCUID() {
 

src/test/java/io/github/thibaultmeyer/cuid/CUIDv2Test.java

@@ -43,6 +43,32 @@ void fromStringInvalid() {
         Assertions.assertEquals("CUID string is invalid: 'invalid-cuid'", exception.getMessage());
     }
 
+    @Test
+    void isValid() {
+
+        // Arrange
+        final String cuidAsString = "n1ht3jch1r23dy9ramd6ts16";
+
+        // Act
+        final boolean isValid = CUID.isValid(cuidAsString);
+
+        // Assert
+        Assertions.assertTrue(isValid);
+    }
+
+    @Test
+    void isValidInvalid() {
+
+        // Arrange
+        final String cuidAsString = "not-a-cuid";
+
+        // Act
+        final boolean isValid = CUID.isValid(cuidAsString);
+
+        // Assert
+        Assertions.assertFalse(isValid);
+    }
+
     @Test
     void randomCUIDv2() {