graphlog: remove unused get_revs() function

hgext/graphlog.py

@@ -14,7 +14,6 b' revision graph is also shown.'
 
 from mercurial.cmdutil import show_changeset
 from mercurial.i18n import _
-from mercurial.node import nullrev
 from mercurial import cmdutil, commands, extensions, scmutil
 from mercurial import hg, util, graphmod, templatekw, revset
 
@@ -227,15 +226,6 b' def ascii(ui, state, type, char, text, c'
     state[0] = coldiff
     state[1] = idx
 
-def get_revs(repo, rev_opt):
-    if rev_opt:
-        revs = scmutil.revrange(repo, rev_opt)
-        if len(revs) == 0:
-            return (nullrev, nullrev)
-        return (max(revs), min(revs))
-    else:
-        return (len(repo) - 1, 0)
-
 def check_unsupported_flags(pats, opts):
     for op in ["newest_first"]:
         if op in opts and opts[op]: