assertTrue(ok);
// CONVERT BACK TO OBO
OBODoc obodoc = convert(ontology);
// test that relation IDs are converted back to symbolic form
Frame tf = obodoc.getTermFrame("GO:0000050");
Clause c = tf.getClause(OboFormatTag.TAG_RELATIONSHIP);
Object v = c.getValue();
// should be converted back to symbolic form
assertEquals("has_part", v);
tf = obodoc.getTermFrame("GO:0004055");
c = tf.getClause(OboFormatTag.TAG_RELATIONSHIP);
v = c.getValue();
// should be converted back to symbolic form
assertEquals("part_of", v);
tf = obodoc.getTypedefFrame("has_part");
Collection<Clause> cs = tf.getClauses(OboFormatTag.TAG_XREF);
assertEquals(1, cs.size());