link to source of magick number

Author: jappeace

Data/HashMap/Internal.hs

@@ -238,6 +238,7 @@ instance NF.NFData2 Leaf where
 -- >>> fromInteger (-3750763034362895579) :: Word64
 
 #if MIN_VERSION_hashable(1,3,1)
+-- fnv constant: https://github.com/haskell-unordered-containers/hashable/blame/c0cd4aa5238a2424d602719da9db69cc01bd17bb/src/Data/Hashable/Class.hs#L207
 type DefaultSalt = 14695981039346656037 -- fromInteger (-3750763034362895579) :: Word64
 #else
 type DefaultSalt = 15868100553162883236 -- old values https://github.com/haskell-unordered-containers/hashable/blame/ade7f97d1c59e9cfbad49b6ed130b90805311758/Data/Hashable/Class.hs#L202