symtable works but not multiple variable

src/main/java/TP2/asd/test_symtable.java

@@ -0,0 +1,15 @@
+package TP2.asd;
+import TP2.asd.Interface.*;
+import TP2.asd.Program.Type_intImp;
+import TP2.asd.SymTable.*;
+public class test_symtable{
+    private static final Type Type_intImp = null;
+
+    public static void main(String[] args){ 
+        SymTable test_symTable = new SymTable();
+        test_symTable.next_layer();
+        //test_symTable.peppapeek();
+        test_symTable.addVar("a", Type_intImp);
+        System.out.print(test_symTable.print_all());
+    }
+}