docs: public void ensureNumBuffersReturned(final int minRequiredAvailable) {
  		if (minRequiredAvailable > this.availableMemory.size() + this.buildSpillRetBufferNumbers) {
  			throw new IllegalArgumentException("More buffers requested available than totally available.");
  		}
  
  		try {
  			while (this.availableMemory.size() < minRequiredAvailable) {
  				this.availableMemory.add(this.buildSpillReturnBuffers.take());
  				this.buildSpillRetBufferNumbers--;
  			}
  		} catch (InterruptedException iex) {
  			throw new RuntimeException("Hash Join was interrupted.");
  		}
  	}