No formalities are necessary for the validity of a lease as between lessor and lessee. Often, the company (the "lessee") leases the mineral rights from the owner (the "lessor"). However, in general, the assignee has privity of estate with a lessor. CITY is also a general contractor and both landlord and lessor. By , the airline struck a wet-lease agreement with Dutch lessor TransAvia. Creditors of the lessor are in a separate class. However, in November 2019 this aircraft was returned to the lessor. In 2016, the aircraft was withdrawn from use and returned to the lessor. The lessor was originally disclosed as an unnamed customer. Hi Fly subsequently returned the aircraft to its lessor along with its remaining A330-300. For a business lessor there are tax advantages to be considered. Canadian Pacific, Union Pacific and lessor CIT Group acquired this locomotive type. GPA grew to be the world's biggest aircraft lessor, worth $4 billion at its peak. The company is the only lessor in the industry with a graduate recruitment programme. Delays resulted in order cancellations, including from the Swedish lessor.