@Test
public void testInsertBefore() {

  ExprStmt stmt = new ExprStmt(new BoolConstantExpr(true));
  BlockStmt b = new BlockStmt(Arrays.asList(stmt), true);
  assertEquals(1, b.getNumStmts());
  b.insertBefore(stmt, new NullStmt());
  assertEquals(2, b.getNumStmts());
  assertTrue(b.getStmt(0) instanceof NullStmt);
  assertEquals(stmt, b.getStmt(1));
}