question: private void itemsArrayToCombinedBuffer ( T [ ] itemsArray ) { final int extra = 2 ; minValue_ = itemsArray [ 0 ] ; maxValue_ = itemsArray [ 1 ] ; System . arraycopy ( itemsArray , extra , combinedBuffer_ , 0 , baseBufferCount_ ) ; long bits = bitPattern_ ; if ( bits > 0 ) { int index = extra + baseBufferCount_ ; for ( int level = 0 ; bits != 0L ; level ++ , bits >>>= 1 ) { if ( ( bits & 1L ) > 0L ) { System . arraycopy ( itemsArray , index , combinedBuffer_ , ( 2 + level ) * k_ , k_ ) ; index += k_ ; } } } }
target:  Loads the Combined Buffer, min and max from the given items array.  The Combined Buffer is always in non-compact form and must be pre-allocated.