Constant MAX_POW_ADJUSTMENT_BLOCK_SPAN 

pub const MAX_POW_ADJUSTMENT_BLOCK_SPAN: usize = _; // 113usize

The largest overall block span used for adjusting Zcash block difficulty.

PoWAveragingWindow(height) + PoWMedianBlockSpan in the Zcash specification, for the height with the largest averaging window, based on

ActualTimespan(height : N) := MedianTime(height) − MedianTime(height − PoWAveragingWindow)

Used to size the buffers that hold difficulty adjustment context. Use pow_adjustment_block_span for the span that actually applies to a block, because ZIP 218 makes the averaging window height-dependent.