Added new modification to Modifiable

Author: mmaehren

src/main/java/de/rub/nds/modifiablevariable/biginteger/BigIntegerModificationFactory.java

@@ -57,6 +57,10 @@ public static BigIntegerShiftRightModification shiftRight(final Integer shift) {
         return new BigIntegerShiftRightModification(shift);
     }
 
+    public static BigIntegerMultiplyModification multiply(final BigInteger factor) {
+        return new BigIntegerMultiplyModification(factor);
+    }
+
     public static VariableModification<BigInteger> sub(final String subtrahend) {
         return sub(new BigInteger(subtrahend));
     }

src/main/java/de/rub/nds/modifiablevariable/util/Modifiable.java

@@ -173,6 +173,10 @@ public static ModifiableBigInteger shiftRightBigInteger(Integer i) {
         return getModifiableBigIntegerWithModification(BigIntegerModificationFactory.shiftRight(i));
     }
 
+    public static ModifiableBigInteger multiplyBigInteger(BigInteger i) {
+        return getModifiableBigIntegerWithModification(BigIntegerModificationFactory.multiply(i));
+    }
+
     public static ModifiableInteger shiftRight(Integer i) {
         return getModifiableIntegerWithModification(IntegerModificationFactory.shiftRight(i));
     }