public static int fnv1a32(int initHash, byte... data) {
    int hash = initHash;
    for (byte datum : data) {
      hash ^= (datum & 0xff);
      hash *= FNV1_PRIME_32;
    }
    return hash;
  }
Computes the hash using the FNV-1a 32-bit hash function, starting with the initial hash.
<p>
The hash generation must always start with {@link #FNV1_32_INIT} as initial hash but this version comes in handy
when generating the hash for multiple bytes consecutively in a loop.

@param initHash the initial hash
@param data     the data to generate the hash for
@return the generated hash
planetiler-core/src/main/java/com/onthegomap/planetiler/util/Hashing.java