Includes at least one floating body, and is characterised in that includes a device fitted inside said body for transforming the movement of the floating body into pneumatic or hydraulic energy and means for transmitting the energy to dry land or to a fixed structure. A second module determines a price for the executed trade, in which the price is specified relative to the valuation andor the valuation with a basis adjustment. The first scanning driving unit is configured to cause the scanning mirror to rotate about a first rotation axis by means of deformation of the frame structure. Accordingly, such automatic modifications to the implementation facilitate a developer’s adopting a contract based approach to web service development.