129It follows from settled case-law that the assessment of the condition relating to the selectivity of the advantage requires a determination as to whether, under a particular legal regime, a national measure is such as to favour ‘certain undertakings or the production of certain goods’ over others which, in the light of the objective pursued by that regime, are in a comparable factual and legal situation. The concept of ‘State aid’ does not refer to State measures which differentiate between undertakings and which are, therefore, prima facie selective where that differentiation arises from the nature or the overall structure of the system of which they form part (see judgment of 21 December 2016, Commission v Hansestadt Lübeck, C‑524/14 P, EU:C:2016:971, paragraph 41 and the case-law cited).