Modify the hiorzontal line in stripe (s) items of forest plot object (fobj).
Passed to abline.
s_hline(fobj, item = NULL, ...)a forest plot object of class 'fobj'
item to be modified, either a number or the name of the column in fobj$dat. If NULL (the default), all items of type 's' are affected
options to be passed to abline
a forest plot object of class 'fobj'