docs: @Override
      public void releaseBuffer ( byte[] buf ) {
          // better safe than sorry: prevent leaks if there is some out of bound access
          Arrays.fill(buf, (byte) 0);
          synchronized ( this.cache ) {
              if ( this.freeBuffers < this.cache.length ) {
                  for ( int i = 0; i < this.cache.length; i++ ) {
                      if ( this.cache[ i ] == null ) {
                          this.cache[ i ] = buf;
                          this.freeBuffers++;
                          return;
                      }
                  }
              }
          }
      }