How to use the qiling.os.posix.syscall.ql_syscall_ftruncate function in qiling

def test_syscall_ftruncate(ql, ftrunc_fd, ftrunc_length, *args):
            target = False
            pathname = ql.file_des[ftrunc_fd].name.split('/')[-1]

            if pathname == "test_syscall_ftruncate.txt":
                print("test => ftruncate(%d, 0x%x)" % (ftrunc_fd, ftrunc_length))
                target = True

            syscall.ql_syscall_ftruncate(ql, ftrunc_fd, ftrunc_length, *args)

            if target:
                real_path = ql_transform_to_real_path(ql, pathname)
                assert os.stat(real_path).st_size == 0x10
                os.remove(real_path)