title: Can zero be used as exception case for MurmurHash3
body: <p>In a specific use case in our organisation I have chosen to use MurmurHash3 (128-bit version) to determine whether a record consisting of multiple elements are unique compared to another record. Choice of algorithm and debate regarding the wisdom of using a hash to determine uniqueness aside, can the value zero (0) be used as an exception value for the hash return?</p>
  
  <p>We are currently using Guava's Hashing to generate the hash on a <code>String</code> input and  exceptions cannot be used to report an exception on a <code>null</code> (which is possible) input. Also, the return value has to be a <em>primitive</em> 64-bit value as it is consumed by an external system that I do not have control over so the equivalent of a <em>null</em> cannot be used to report on the exception either.</p>
  
  <p><strong>Note:</strong> Expected range of characters in the input string is in the Basic Latin and Latin-1 unicode blocks. No NUL characters.</p>