FIG. 7A is a schematic drawing showing a front view of the first example of an adaptor 400; FIG. 7B is a schematic drawing showing a top view of the adaptor shown in FIG. 7A; FIG. 7C is a cross-sectional view through the adaptor shown in FIG. 7A along line C-C; and FIG. 7D is a perspective view of the adaptor shown in FIG. 7A. The adaptor 400 is provided with an inlet opening 105 b, an inlet 109 c