How to use the hl7apy.core.Segment function in hl7apy

def test_allow_infinite_children(self):
        qpd = Segment('QPD', validation_level=VALIDATION_LEVEL.STRICT)  # last field is varies
        self.assertTrue(qpd.allow_infinite_children)
        pid = Segment('PID', validation_level=VALIDATION_LEVEL.STRICT)  # last field is not varies
        self.assertFalse(pid.allow_infinite_children)
        zin = Segment('ZIN', validation_level=VALIDATION_LEVEL.STRICT)  # z segment
        self.assertTrue(zin.allow_infinite_children)

        qpd.qpd_4 = 'abc'
        qpd.add_field('qpd_4')

        zin.add(Field('ZIN_100', validation_level=VALIDATION_LEVEL.STRICT))
        zin.zin_4 = 'abc'
        zin.add_field('zin_4')

def test_add_segment_to_message_mix(self):
        a = Message('OML_O33',  validation_level=VALIDATION_LEVEL.TOLERANT)
        msh = Segment('MSH', validation_level=VALIDATION_LEVEL.TOLERANT)
        pid = Segment('PID', validation_level=VALIDATION_LEVEL.TOLERANT)
        g = Group('OML_O33_PATIENT')
        g.add(pid)
        a.add(msh)
        a.add(g)

def test_assign_complex_field_datatype_by_get(self):
        p = Segment('PID')
        p.pid_5 = 'test^test'
        self.assertEqual(p.pid_5.xpn_1.to_er7(), 'test')
        self.assertEqual(p.pid_5.xpn_2.to_er7(), 'test')

        m = Message('RSP_K21', reference=self.rsp_k21_mp, validation_level=VALIDATION_LEVEL.TOLERANT)
        p = m.rsp_k21_query_response.add_segment('pid')
        p.pid_5 = 'test^test'
        self.assertEqual(p.pid_5.xpn_1.to_er7(), 'test')
        self.assertEqual(p.pid_5.xpn_2.to_er7(), 'test')

def test_add_child_with_different_version(self):
        g = Group('RSP_K21_QUERY_RESPONSE', version='2.5')
        s = Segment('QPD', version='2.4')
        self.assertRaises(OperationNotAllowed, g.add, s)

def test_add_not_allowed_fields_to_known_segments(self):
        s = Segment('PID', validation_level=VALIDATION_LEVEL.STRICT)
        self.assertRaises(ChildNotValid, s.add, Field('spm_10'))
        s = Segment('PID')
        self.assertRaises(ChildNotValid, s.add, Field('spm_10'))

        m = Message('RSP_K21', validation_level=VALIDATION_LEVEL.STRICT, reference=self.rsp_k21_mp)
        s = m.add_segment('QPD')
        self.assertRaises(ChildNotValid, s.add, Field('spm_10'))

        m = Message('RSP_K21', validation_level=VALIDATION_LEVEL.TOLERANT, reference=self.rsp_k21_mp)
        s = m.add_segment('QPD')
        self.assertRaises(ChildNotValid, s.add, Field('spm_10'))

def test_add_child_with_different_validation_level(self):
        g = Group('RSP_K21_QUERY_RESPONSE', validation_level=VALIDATION_LEVEL.STRICT)
        s = Segment('PID', validation_level=VALIDATION_LEVEL.TOLERANT)
        self.assertRaises(OperationNotAllowed, g.add, s)

        g = Group('RSP_K21_QUERY_RESPONSE', validation_level=VALIDATION_LEVEL.TOLERANT)
        s = Segment('PID', validation_level=VALIDATION_LEVEL.STRICT)
        self.assertRaises(OperationNotAllowed, g.add, s)

qak.qak_3 = "Q22^Specimen Labeling Instructions^IHE_LABTF"
                qak.qak_4 = "1"
                # add the QAK segment to the RSP_K11 message
                response.add(qak)
                # copy the QPD segment from the incoming message
                response.QPD = m.QPD
                # create a PID segment
                response.PID.PID_1 = '1'
                response.PID.PID_5.PID_5_1 = 'PATIENT_SURNAME'
                response.PID.PID_5.PID_5_2 = 'PATIENT_NAME'
                response.PID.PID_6 = "19800101"
                response.PID.PID_7 = "F"
                # create a SPM segment
                spm = Segment("SPM")
                # create an OBR segment
                obr = Segment("OBR")
                spm.SPM_1 = '1'
                spm.SPM_2 = "12345"
                obr.OBR_4 = "ORDER^DESCRIPTION"
                # add spm and obr to the RSP_K11 response
                response.add(spm)
                response.add(obr)
            else:
                response = LIP.nak(m)
        return response.to_mllp() # encode to ER7

if _valid_z_message_name(name):
                reference = ('sequence', ())
                super(Message, self).__init__(name, None, reference, version,
                                              validation_level)
            else:
                raise

        if encoding_chars is None:
            encoding_chars = get_default_encoding_chars(version)
        # TODO: Change it to support message profiles
        try:
            msh_reference = self.structure_by_name['MSH']['ref']
        except (KeyError, TypeError):
            msh_reference = None

        self.msh = Segment('MSH', version=self.version, validation_level=self.validation_level,
                           reference=msh_reference)
        self.encoding_chars = encoding_chars
        self.msh.msh_7 = datetime.datetime.now().strftime('%Y%m%d%H%M%S')
        self.msh.msh_12 = self.version

def add(self, obj):
        super(Segment, self).add(obj)
        # updates the index of the last children not allowed
        if obj.name and self.allow_infinite_children:
            field_index = int(obj.name[4:])
            if field_index > self._last_child_index:
                self._last_child_index = field_index