     md5 key
 
   try_histocache : -> 
+    return false if !ENABLE_SERVER_HISTOCACHE
     proposal = fetch(@props.proposal)
     histocache_key = @histocache_key()
 

    # extraction from @try_histocache
    proposal = fetch(@props.proposal)
    histocache_key = @histocache_key()
    if proposal.histocache?[histocache_key]
      if histocache_key != @local.histocache?.hash
        @local.histocache =
          hash: histocache_key 

  save hist


ENABLE_SERVER_HISTOCACHE = true 

window.Histogram = ReactiveComponent
  displayName : 'Histogram'

