def METHOD_NAME():
    g = rdflib.ConjunctiveGraph()
    g.get_context("urn:a").add(
        (rdflib.URIRef("urn:1"), rdflib.URIRef("urn:2"), rdflib.URIRef("urn:3"))
    )
    g.get_context("urn:b").add(
        (rdflib.URIRef("urn:1"), rdflib.URIRef("urn:2"), rdflib.URIRef("urn:3"))
    )
    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 b"{}" not in s  # no empty graphs!