Java SE (Java Platform, Standard Edition)

Hi Guys.

Is there any good reasons why an RuntimeException is not thrown although it should?
Look at the following code snippset:
Note: colConstraints is a HashMap object.

Set<String> newValueSet = .... (here is the object initialized with some values)
for (String key : newValuesSet) {
				if (colConstraints.containsKey(key)) {
					System.out.println(colConstraints + "  " + key);
					throw new RuntimeException(
							"SQLQueryBuilder.UpdateQuery: Misplacement " + key
									+ " cannot be a primary or foreign key");
				}
			}

I wonder why I dont get any error thrown even though there are cases where key is contained within colConstraints.
Best regrads.

Edmond