question: @ SuppressWarnings ( "fallthrough" ) static void murmurhash3_x64_128 ( byte [ ] key , int offset , int len , int seed , LongPair out ) { long h1 = seed & 0x00000000FFFFFFFFL ; long h2 = seed & 0x00000000FFFFFFFFL ; final long c1 = 0x87c37b91114253d5L ; final long c2 = 0x4cf5ad432745937fL ; int roundedEnd = offset + ( len & 0xFFFFFFF0 ) ; for ( int i = offset ; i < roundedEnd ; i += 16 ) { long k1 = getLongLittleEndian ( key , i ) ; long k2 = getLongLittleEndian ( key , i + 8 ) ; k1 *= c1 ; k1 = Long . rotateLeft ( k1 , 31 ) ; k1 *= c2 ; h1 ^= k1 ; h1 = Long . rotateLeft ( h1 , 27 ) ; h1 += h2 ; h1 = h1 * 5 + 0x52dce729 ; k2 *= c2 ; k2 = Long . rotateLeft ( k2 , 33 ) ; k2 *= c1 ; h2 ^= k2 ; h2 = Long . rotateLeft ( h2 , 31 ) ; h2 += h1 ; h2 = h2 * 5 + 0x38495ab5 ; } long k1 = 0 ; long k2 = 0 ; switch ( len & 15 ) { case 15 : k2 = ( key [ roundedEnd + 14 ] & 0xffL ) << 48 ; case 14 : k2 |= ( key [ roundedEnd + 13 ] & 0xffL ) << 40 ; case 13 : k2 |= ( key [ roundedEnd + 12 ] & 0xffL ) << 32 ; case 12 : k2 |= ( key [ roundedEnd + 11 ] & 0xffL ) << 24 ; case 11 : k2 |= ( key [ roundedEnd + 10 ] & 0xffL ) << 16 ; case 10 : k2 |= ( key [ roundedEnd + 9 ] & 0xffL ) << 8 ; case 9 : k2 |= ( key [ roundedEnd + 8 ] & 0xffL ) ; k2 *= c2 ; k2 = Long . rotateLeft ( k2 , 33 ) ; k2 *= c1 ; h2 ^= k2 ; case 8 : k1 = ( ( long ) key [ roundedEnd + 7 ] ) << 56 ; case 7 : k1 |= ( key [ roundedEnd + 6 ] & 0xffL ) << 48 ; case 6 : k1 |= ( key [ roundedEnd + 5 ] & 0xffL ) << 40 ; case 5 : k1 |= ( key [ roundedEnd + 4 ] & 0xffL ) << 32 ; case 4 : k1 |= ( key [ roundedEnd + 3 ] & 0xffL ) << 24 ; case 3 : k1 |= ( key [ roundedEnd + 2 ] & 0xffL ) << 16 ; case 2 : k1 |= ( key [ roundedEnd + 1 ] & 0xffL ) << 8 ; case 1 : k1 |= ( key [ roundedEnd ] & 0xffL ) ; k1 *= c1 ; k1 = Long . rotateLeft ( k1 , 31 ) ; k1 *= c2 ; h1 ^= k1 ; } h1 ^= len ; h2 ^= len ; h1 += h2 ; h2 += h1 ; h1 = fmix64 ( h1 ) ; h2 = fmix64 ( h2 ) ; h1 += h2 ; h2 += h1 ; out . val1 = h1 ; out . val2 = h2 ; }
target:  Returns the MurmurHash3_x64_128 hash, placing the result in "out". 