// Allocate regions larger than pool buffer size to force new allocations
        RdmaMemoryRegion region1 = bufferManager.getSendRegion(131072); // 128KB > 64KB pool size
        RdmaMemoryRegion region2 = bufferManager.getSendRegion(131072); // Another large allocation

        assertTrue(bufferManager.getTotalAllocated() > initialAllocated, "Total allocated should increase");

    
    // Test buffer allocation
    RdmaMemoryRegion region = manager.getSendRegion(1024);
    assertNotNull(region);
    assertTrue(region.getSize() >= 1024);
    
    // Test buffer release
    manager.releaseSendRegion(region);
    
    // Test reuse
    RdmaMemoryRegion region2 = manager.getSendRegion(1024);
    assertNotNull(region2);
    
    manager.cleanup();
}
```

        try (RdmaBufferManager bufferManager = new RdmaBufferManager(provider)) {
            // Test basic buffer allocation
            RdmaMemoryRegion sendRegion = bufferManager.getSendRegion(4096);
            assertNotNull(sendRegion, "Send region should not be null");
            assertTrue(sendRegion.getSize() >= 4096, "Send region should be at least 4KB");

     *
     * @param minSize minimum required size
     * @return memory region for sending
     * @throws IOException if allocation fails
     */
    public RdmaMemoryRegion getSendRegion(int minSize) throws IOException {
        if (minSize <= sendBufferSize) {
            RdmaMemoryRegion region = availableSendRegions.poll();
            if (region != null) {
                region.getBuffer().clear();