Thibodaux and Baker were performing services in connection with work which was part of the business, trade and occupation of Sun Oil Company, or so closely related thereto as to become an integral part thereof.” 49 So.2d at 854 (emphasis added). The underscored language, although not expressly announced as the standard for determining trade, business or occupation, became the basis for the so-called integral relationship test which was used in cases following Thibodaux to liberally construe tort immunity in favor of principals. Under the liberal integral relationship test — also referred to as the “essential to business” test — few instances of contract work were held not to be a part of the principal’s business. See Foster v. Western Electric Co., 258 So.2d 153 (La.App. 2d Cir.1972) (<HOLDING>); Slocum v. Lamartiniere, 369 So.2d 201
holding a jury question existed as to whether a patient consented to an operation and whether the operation received was substantially similar to the operation to which the patient consented so as to be within the scope of the consent holding there are three tests used to determine whether an employee was engaged in an activity that is part of the owners trade business or occupation holding that in pennsylvania there is a rule that proof of the ownership of a business vehicle involved in an accident raises a presumption that the operation of the automobile was for the owners business purposes holding that care of the grounds was part of the business of the hospital holding that the operation of a plant cafeteria was part of the plant owners business