import click


def get_help_msg(command):
    """
    Print full help message of click def <function>

    Ex: print_help_msg(testcmd)

    :param command: function that has the click command decorator and help option
    :return: a string containting the @click.command() <function> help message
    """
    with click.Context(command) as ctx:
        # click.echo(command.get_help(ctx))
        return command.get_help(ctx)