def delegate(self, delegee_gidfile, caller_keyfile, caller_gidfile):
"""
Return a delegated copy of this credential, delegated to the
specified gid's user.
"""
# get the gid of the object we are delegating
object_gid = self.get_gid_object()
object_hrn = object_gid.get_hrn()
# the hrn of the user who will be delegated to
delegee_gid = GID(filename=delegee_gidfile)
delegee_hrn = delegee_gid.get_hrn()
#user_key = Keypair(filename=keyfile)
#user_hrn = self.get_gid_caller().get_hrn()
subject_string = "%s delegated to %s" % (object_hrn, delegee_hrn)
dcred = Credential(subject=subject_string)
dcred.set_gid_caller(delegee_gid)
dcred.set_gid_object(object_gid)
dcred.set_parent(self)
dcred.set_expiration(self.get_expiration())
dcred.set_privileges(self.get_privileges())
dcred.get_privileges().delegate_all_privileges(True)
#dcred.set_issuer_keys(keyfile, delegee_gidfile)
dcred.set_issuer_keys(caller_keyfile, caller_gidfile)
dcred.encode()
dcred.sign()
return dcred
