Intent to close ISSUE-142

I updated both the syntax and the API spec as well as the test suite to
remove property generators. Unless I hear objections I will therefore close
ISSUE-142 [1] in 24 hours.


Cheers,
Markus


[1] https://github.com/json-ld/json-ld.org/issues/142


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Markus Lanthaler
@markuslanthaler