May 7, 1987. June 15, 1987. Present: HENNESSEY, C.J., WILKINS, NOLAN, LYNCH, JJ. Contract, What constitutes, Lease of real estate, Option. Landlord and Tenant, Extension of lease, Lease as contract, Option to purchase, Renewal of lease. Attorney at Law, Disqualification. Witness, Attorney as witness. Evidence, Judicial notice. A so-called letter of intent containing an outline of matters discussed by a lessor and its lessee pursuant to the lessee's decision to exercise its option to renew a lease