1 files changed, 38 insertions, 5 deletions

diff --git a/src/ch/epfl/xblast/ArgumentChecker.java b/src/ch/epfl/xblast/ArgumentChecker.java
index 589c197..a8ca31a 100644
--- a/src/ch/epfl/xblast/ArgumentChecker.java
+++ b/src/ch/epfl/xblast/ArgumentChecker.java
@@ -1,5 +1,10 @@
 package ch.epfl.xblast;
 
+import ch.epfl.cs108.Sq;
+
+import java.util.Collection;
+import java.util.Objects;
+
 /**
  * ArgumentChecker.
  *
@@ -11,15 +16,43 @@ public final class ArgumentChecker {
     /**
      * Returns the given value if it is non-negative.
      *
-     * @param value the tested value
+     * @param v the tested value
      * @return the given value if non-negative
      * @throws IllegalArgumentException if the value is inferior to 0
      */
-    public static int requireNonNegative(int value) {
-        if (value >= 0)
-            return value;
-        else
+    public static int requireNonNegative(int v) {
+        if (v < 0)
+            throw new IllegalArgumentException();
+
+        return v;
+    }
+
+    /**
+     * Requires the given Collection to be non-empty and returns it or throw an IllegalArgumentException otherwise.
+     *
+     * @param c   the Collection to check
+     * @param <T> the Collection type
+     * @return the checked Collection
+     */
+    public static <T extends Collection> T requireNonEmpty(T c) {
+        if (Objects.requireNonNull(c).isEmpty())
             throw new IllegalArgumentException();
+
+        return c;
+    }
+
+    /**
+     * Requires the given sequence to be non-empty and returns it or throw an IllegalArgumentException otherwise.
+     *
+     * @param s   the sequence to check
+     * @param <T> the sequence type
+     * @return the checked sequence
+     */
+    public static <T extends Sq> T requireNonEmpty(T s) {
+        if (Objects.requireNonNull(s).isEmpty())
+            throw new IllegalArgumentException();
+
+        return s;
     }
 
 }