def METHOD_NAME():
    g = rdflib.ConjunctiveGraph()
    g.get_context("urn:a").add(
        (rdflib.URIRef("urn:1"), rdflib.URIRef("urn:p1"), rdflib.URIRef("urn:o1"))
    )
    g.get_context("urn:b").add(
        (rdflib.URIRef("urn:1"), rdflib.URIRef("urn:p2"), rdflib.URIRef("urn:o2"))
    )
    assert len(g.get_context("urn:a")) == 1
    assert len(g.get_context("urn:b")) == 1
    s = g.serialize(format="trig", encoding="latin-1")
    assert len(re.findall(b"p1", s)) == 1
    assert len(re.findall(b"p2", s)) == 1
    assert b"{}" not in s  # no empty graphs!