assertNotNull(region, "Send region should not be null");
        assertTrue(region.getSize() >= 1024, "Region should be at least requested size");
        assertTrue(region.hasAccess(RdmaAccess.LOCAL_READ), "Should have local read access");
        assertTrue(region.hasAccess(RdmaAccess.REMOTE_READ), "Should have remote read access");

        // Verify provider was called

        assertEquals(1024, region.getSize(), "Size should match buffer size");
        assertTrue(region.hasAccess(RdmaAccess.LOCAL_READ), "Should have local read access");
        assertTrue(region.hasAccess(RdmaAccess.LOCAL_WRITE), "Should have local write access");
        assertFalse(region.hasAccess(RdmaAccess.REMOTE_READ), "Should not have remote read access");

        // Test cleanup
        region.close();

    public int getRemoteKey() { return remoteKey; }
    public long getAddress() { return address; }
    public int getSize() { return buffer.remaining(); }
    
    public boolean hasAccess(RdmaAccess access) {
        return accessFlags.contains(access);
    }
    
    /**
     * Invalidate this memory region
     */
    public abstract void invalidate();
    

    /**
     * Check if region has specific access permission
     *
     * @param access access permission to check
     * @return true if access is allowed, false otherwise
     */
    public boolean hasAccess(RdmaAccess access) {
        return accessFlags.contains(access);
    }

    /**
     * Check if memory region is still valid
     *
     * @return true if valid, false if invalidated
     */