. 2019 2019 these conduits are described in note 11 . the commercial paper issuances and commitments of the conduits to provide funding are supported by liquidity asset purchase agreements and backup liquidity lines of credit , the majority of which are provided by us . in addition , we provide direct credit support to the conduits in the form of standby letters of credit . our commitments under liquidity asset purchase agreements and back-up lines of credit totaled $ 28