@staticmethod
def _display_role(roles):
    """ gets a list of available roles and
        asks the user to select the role they want to assume
        """
    role_strs = []
    last_account = None
    for i, role in enumerate(roles):
        if not role:
            continue
        current_account = role.friendly_account_name
        if not current_account == last_account:
            role_strs.append(current_account)
            last_account = current_account
        role_strs.append('      [ {} ]: {}'.format(i, role.friendly_role_name))
    return role_strs
