### Question:
SmartUnsafeMemoryManager extends UnsafeMemoryManager { @Override @Contract(pure = true) public boolean isValid() { if (DEBUG >= LOG_TRACE) log.trace("Checking if the native library is loaded."); try { return super.isValid() && c_is_valid(); } catch (final UnsatisfiedLinkError e) { return false; } } private  SmartUnsafeMemoryManager(); @Override @Contract(pure = true) boolean isValid(); @Override @Contract(pure = true) long getPageSize(); @Override @Contract(value = " -> fail", pure = true) @SuppressWarnings({"deprecation", "PMD.DataflowAnomalyAnalysis"}) long getHugepageSize(); @Override @Contract(pure = true) @SuppressWarnings("BooleanParameter") long allocate(long bytes, boolean huge, boolean lock); @Override @SuppressWarnings("BooleanParameter") void free(long address, long bytes, final boolean huge, final boolean lock); @Override @Contract(pure = true) @SuppressWarnings({"deprecation", "BooleanParameter", "IOResourceOpenedButNotSafelyClosed", "resource"}) long mmap(final @NotNull File file, final boolean huge, final boolean lock); @Override @SuppressWarnings({"deprecation", "BooleanParameter", "PMD.DataflowAnomalyAnalysis"}) void munmap(final long address, final @NotNull File file, final boolean huge, final boolean lock); @Override @Contract(pure = true) @SuppressWarnings("deprecation") @SuppressFBWarnings("") long virt2phys(final long address); @Override @Contract(value = "_, _, _ -> fail", pure = true) @SuppressWarnings({"deprecation", "BooleanParameter"}) @NotNull DmaMemory dmaAllocate(final long bytes, final boolean huge, final boolean lock);  }### Answer:
@Test @DisplayName("isValid()") void isValid() { assumeTrue(mmanager != null); assertThat(mmanager.isValid()).isTrue(); }