'Check if target member in target group.
:param target_group: target group
:param target_member: target member
:return: True if target member in target group, else False
:raises NexentaException: if target group doesn\'t exist'

def _target_member_in_target_group(self, target_group, target_member):

    members = self.nms.stmf.list_targetgroup_members(target_group)
    if (not members):
        return False
    return (target_member in members)
