check if multiplicity of present TLVs conforms to the standard
        :param tlv_type_count: dict containing counte-per-TLV

def _tlv_multiplicities_check(tlv_type_count):
        """
        check if multiplicity of present TLVs conforms to the standard
        :param tlv_type_count: dict containing counte-per-TLV
        """

        # * : 0..n, 1 : one and only one.
        standard_multiplicities = {
            LLDPDUEndOfLLDPDU.__name__: 1,
            LLDPDUChassisID.__name__: 1,
            LLDPDUPortID.__name__: 1,
            LLDPDUTimeToLive.__name__: 1,
            LLDPDUPortDescription: '*',
            LLDPDUSystemName: '*',
            LLDPDUSystemDescription: '*',
            LLDPDUSystemCapabilities: '*',
            LLDPDUManagementAddress: '*'
        }

        for tlv_type_name in standard_multiplicities:

            standard_tlv_multiplicity = \
                standard_multiplicities[tlv_type_name]
            if standard_tlv_multiplicity == '*':
                continue

            try:
                if tlv_type_count[tlv_type_name] != standard_tlv_multiplicity:
                    raise LLDPInvalidTLVCount(
                        'Invalid number of entries for TLV type '
                        '{} - expected {} entries, got '
                        '{}'.format(tlv_type_name,
                                    standard_tlv_multiplicity,
                                    tlv_type_count[tlv_type_name]))

            except KeyError:
                raise LLDPInvalidTLVCount('Missing TLV layer of type '
                                          '{}.'.format(tlv_type_name))