The ornamental design for a beveragecontainercap, as shown and described.
FIG. 1 is a first top perspective view of a beverage container cap with a loop in a stowed position.
FIG. 2 is a second top perspective view of the beverage container cap of FIG. 1 with the loop in an unstowed position.
FIG. 3 is a front elevation view of the beverage container cap of FIG. 1 with the loop in a stowed position.
FIG. 4 is a back elevation view thereof.
FIG. 5 is a right-side elevation view thereof.
FIG. 6 is a left-side elevation view thereof.
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The dashed lines and the areas within them in FIGS. 1-5 and 8 depict a threaded lower portion of the beverage container cap that forms no part of the claimed design. The dashed lines and the areas within them in FIG. 6 depict the environment of a vacuum flask that forms no part of the claimed design.