Nested "@id" elements are not processed correctly in framing

[hsolbrig]

Changing the @id alias in an inner context doesn't work correctly.

Synopsis:

{   "@context": {
            "namespace": "@id", 
             "contents": {
                  "@context": {
                       "uri": "@id
                  }
              }
      }
}

Doesn't work correctly in framing -- both the inner and the outer element are returned as "namespace"

The attached file is a complete unit test.

test_ld_11_issue.txt

[cmungall]

Would be great to see this fixed!