The value corresponds to: ` 2^64 / phi - 1 ` where phi is the Golden Ratio and 1 is subtracted to avoid the value being a multiple of 2 (that would throw away one bit of information from the resultant hash value). See https://en.wikipedia.org/wiki/Hash_function#Fibonacci_hashing.
Declared in <bslh_fibonaccibadhashwrapper.h>
static
bsls::Types::Uint64 const k_FIBONACCI_HASH_MULTIPLIER = 11400714819323198485ull;