The ornamental design for a trashbagholder, as shown and described.
FIG. 1 is a top, left side and front perspective view of a trash bag holder
showing my new design, the opposite side perspective view being a mirror
image of the shown; and,
FIG. 2 is a front elevational view thereof.
The post in the drawing is shown broken away to indicate indeterminate
length, and the rear view of the post is plain and unornamented.