The key can be retrieved via methods Location#toBlockKey() and
Block#getBlockKey()
World provides lookup for blocks by long key via method World#getBlockAtKey(long)
The formatting for the key is as follows:
10 bit y|27 bit z|27 bit x
The y value is considered unsigned while z and x are considered two's complement
Y range: [0, 1023]
X, Z range: [-67 108 864, 67 108 863]
Checked encoding and decoding via https://gist.github.com/Spottedleaf/74f4e241012ca2fa67d8f1c7e8e34722