refactor: clean code

Signed-off-by: Thibault Meyer <meyer.thibault@gmail.com>

Author: thibaultmeyer

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

@@ -117,12 +117,24 @@ public static boolean isValid(final String cuidAsString) {
 
         return cuidAsString != null
             && (cuidAsString.length() == CUIDv1.LENGTH_STANDARD && cuidAsString.startsWith(CUIDv1.START_CHARACTER) // Version 1
-            || (cuidAsString.length() > 0)) // Version 2
+            || (!cuidAsString.isEmpty())) // Version 2
             && cuidAsString.chars()
             .filter(c -> !((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')))
             .count() == 0;
     }
 
+    /**
+     * Always return non-negative value.
+     *
+     * @param i the integer value
+     * @return a non-negative value
+     * @since 2.0.3
+     */
+    private static int safeAbs(final int i) {
+
+        return i == Integer.MIN_VALUE ? 0 : Math.abs(i);
+    }
+
     /**
      * {@inheritDoc}
      *
@@ -177,11 +189,6 @@ public int hashCode() {
         return Objects.hash(value);
     }
 
-    // Always return non-negative value (including Integer.MIN_VALUE)
-    private static int safeAbs(int a) {
-        return a == Integer.MIN_VALUE ? 0 : Math.abs(a);
-    }
-
     /**
      * CUID Version 1.
      *