Complex BGPs do not parse as triples

[jpmccu]

Here's some example code. parser.expandTriples() makes a hash of this. See PR #622

def test_complex_sparql_construct():

    g = Graph()
    q = '''select ?subject ?study ?id where {
    ?s a <urn:Person>;
      <urn:partOf> ?c;
      <urn:hasParent> ?mother, ?father;
      <urn:id> [ a <urn:Identifier>; <urn:has-value> ?id].
    }'''
    g.query(q)

[jpmccu]

Now fixed by PR #622.