Creates the arg parsers needed for the identity command and
    its subcommands.

def add_identity_parser(subparsers, parent_parser):
    """Creates the arg parsers needed for the identity command and
    its subcommands.
    """
    # identity
    parser = subparsers.add_parser(
        'identity',
        help='Works with optional roles, policies, and permissions',
        description='Provides subcommands to work with roles and policies.')

    identity_parsers = parser.add_subparsers(
        title="subcommands",
        dest="subcommand")

    identity_parsers.required = True

    # policy
    policy_parser = identity_parsers.add_parser(
        'policy',
        help='Provides subcommands to display existing policies and create '
        'new policies',
        description='Provides subcommands to list the current policies '
        'stored in state and to create new policies.')

    policy_parsers = policy_parser.add_subparsers(
        title='policy',
        dest='policy_cmd')

    policy_parsers.required = True

    # policy create
    create_parser = policy_parsers.add_parser(
        'create',
        help='Creates batches of sawtooth-identity transactions for setting a '
        'policy',
        description='Creates a policy that can be set to a role or changes a '
        'policy without resetting the role.')

    create_parser.add_argument(
        '-k', '--key',
        type=str,
        help='specify the signing key for the resulting batches')

    create_target_group = create_parser.add_mutually_exclusive_group()

    create_target_group.add_argument(
        '-o', '--output',
        type=str,
        help='specify the output filename for the resulting batches')

    create_target_group.add_argument(
        '--url',
        type=str,
        help="identify the URL of a validator's REST API",
        default='http://localhost:8008')

    create_parser.add_argument(
        '--wait',
        type=int,
        default=15,
        help="set time, in seconds, to wait for the policy to commit when "
             "submitting to the REST API.")

    create_parser.add_argument(
        'name',
        type=str,
        help='name of the new policy')

    create_parser.add_argument(
        'rule',
        type=str,
        nargs="+",
        help='rule with the format "PERMIT_KEY <key>" or "DENY_KEY <key> '
        '(multiple "rule" arguments can be specified)')

    # policy list
    list_parser = policy_parsers.add_parser(
        'list',
        help='Lists the current policies',
        description='Lists the policies that are currently set in state.')

    list_parser.add_argument(
        '--url',
        type=str,
        help="identify the URL of a validator's REST API",
        default='http://localhost:8008')

    list_parser.add_argument(
        '--format',
        default='default',
        choices=['default', 'csv', 'json', 'yaml'],
        help='choose the output format')

    # role
    role_parser = identity_parsers.add_parser(
        'role',
        help='Provides subcommands to display existing roles and create '
        'new roles',
        description='Provides subcommands to list the current roles '
        'stored in state and to create new roles.')

    role_parsers = role_parser.add_subparsers(
        title='role',
        dest='role_cmd')

    role_parsers.required = True

    # role create
    create_parser = role_parsers.add_parser(
        'create',
        help='Creates a new role that can be used to enforce permissions',
        description='Creates a new role that can be used to enforce '
        'permissions.')

    create_parser.add_argument(
        '-k', '--key',
        type=str,
        help='specify the signing key for the resulting batches')

    create_parser.add_argument(
        '--wait',
        type=int,
        default=15,
        help='set time, in seconds, to wait for a role to commit '
        'when submitting to  the REST API.')

    create_target_group = create_parser.add_mutually_exclusive_group()

    create_target_group.add_argument(
        '-o', '--output',
        type=str,
        help='specify the output filename for the resulting batches')

    create_target_group.add_argument(
        '--url',
        type=str,
        help="the URL of a validator's REST API",
        default='http://localhost:8008')

    create_parser.add_argument(
        'name',
        type=str,
        help='name of the role')

    create_parser.add_argument(
        'policy',
        type=str,
        help='identify policy that role will be restricted to')

    # role list
    list_parser = role_parsers.add_parser(
        'list',
        help='Lists the current keys and values of roles',
        description='Displays the roles that are currently set in state.')

    list_parser.add_argument(
        '--url',
        type=str,
        help="identify the URL of a validator's REST API",
        default='http://localhost:8008')

    list_parser.add_argument(
        '--format',
        default='default',
        choices=['default', 'csv', 'json', 'yaml'],
        help='choose the output format')