How to use the bloom.git.get_current_branch function in bloom

if retcode != 0 and not args.continue_on_error:
            print('')
            info("Stopping branching, to continue pass '--continue-on-error'")
    except CalledProcessError as err:
        # No need for a trackback here, a git call probably failed
        print_exc(traceback.format_exc())
        error(str(err))
        retcode = 1
    except Exception as err:
        # Unhandled exception, print traceback
        print_exc(traceback.format_exc())
        error(str(err))
        retcode = 2
    if retcode == 0:
        info("Working branch: " + ansi('boldon') + \
            str(get_current_branch()) + ansi('reset'))
    sys.exit(retcode)

def get_upstream_meta(upstream_dir, ros_distro):
    meta = None
    directory = os.getcwd()
    with change_directory(upstream_dir):
        if get_root() is not None:  # If in a git repo
            current_branch = get_current_branch()
        else:
            current_branch = None
        name, version, packages = get_package_data(current_branch, quiet=False, release_directory=directory)
    meta = {
        'name': name,
        'version': version,
        'type': 'package.xml'
    }
    return meta

def _trim(config, force, directory):
    debug("_trim(" + str(config) + ", " + str(force) + ", " +
          str(directory) + ")")
    if config['trimbase'] != '':
        warning("It looks like the trim operation has already been done, "
                "nested trimming is not supported.")
        if force:
            warning("Proceeding anyways because of '--force'")
        else:
            warning("If you would like to continue anyways use '--force'")
            return None
    current_branch = get_current_branch(directory)
    if current_branch is None:
        error("Could not determine current branch.", exit=True)
    config['trimbase'] = get_commit_hash(current_branch)
    tmp_dir = tempfile.mkdtemp()
    try:
        # Buckup trim sub directory
        git_root = get_root()
        sub_dir = os.path.join(git_root, config['trim'])
        storage = os.path.join(tmp_dir, config['trim'])
        shutil.copytree(sub_dir, storage)
        # Clear out any untracked files
        execute_command('git clean -fdx', cwd=directory)
        # Collect al files (excluding .git)
        items = []
        for item in os.listdir(git_root):
            if item in ['.git', '..', '.']:

def trim(sub_dir=None, force=False, undo=False, directory=None):
    # Get the current branch
    current_branch = get_current_branch(directory)
    # Ensure the current branch is valid
    if current_branch is None:
        error("Could not determine current branch, are you in a git repo?",
              exit=True)
    # Construct the patches branch
    patches_branch = 'patches/' + current_branch
    try:
        # See if the patches branch exists
        if branch_exists(patches_branch, False, directory=directory):
            if not branch_exists(patches_branch, True, directory=directory):
                track_branches(patches_branch, directory)
        else:
            error("No patches branch (" + patches_branch + ") found, cannot "
                  "perform trim.", exit=True)
        # Get the parent branch from the patches branch
        config = get_patch_config(patches_branch, directory=directory)

if create_dst_branch:
            info(" " * 22 + "- The specified destination branch, " +
                 ansi('boldon') + dst + ansi('reset') +
                 ", does not exist; it will be created from the source "
                 "branch " + ansi('boldon') + src + ansi('reset'))
        if create_dst_patches_branch:
            info(" " * 22 + "- The destination patches branch, " +
                 ansi('boldon') + dst_patches + ansi('reset') +
                 ", does not exist; it will be created")
        info(" " * 22 + "- The working branch will be set to " +
             ansi('boldon') + dst + ansi('reset'))
        if not maybe_continue():
            error("Answered no to continue, aborting.", exit=True)

    # Make changes to the layout
    current_branch = get_current_branch(directory)
    try:
        # Change to the src branch
        checkout(src, directory=directory)
        # Create the dst branch if needed
        if create_dst_branch:
            create_branch(dst, changeto=True, directory=directory)
        else:
            checkout(dst, directory=directory)
        # Create the dst patches branch if needed
        if create_dst_patches_branch:
            create_branch(dst_patches, orphaned=True, directory=directory)
        # Create the starting config data if it does not exist
        patches_ls = ls_tree(dst_patches, directory=directory)
        if 'patches.conf' not in patches_ls:
            # Patches config not setup, set it up
            config = {

def get_releaser_history(self):
        # Assumes that this is called in the target branch
        patches_branch = 'patches/' + get_current_branch()
        raw = show(patches_branch, 'releaser_history.json')
        return None if raw is None else json.loads(raw)

def handle_arguments(self, args):
        self.interactive = args.interactive
        self.prefix = args.prefix
        if args.src is None:
            current_branch = get_current_branch()
            if current_branch is None:
                error("Could not determine current branch.", exit=True)
            self.src = current_branch
        else:
            self.src = args.src
        self.name = args.name
        self.release_inc = args.release_increment

def get_releaser_history(self):
        # Assumes that this is called in the target branch
        patches_branch = 'patches/' + get_current_branch()
        raw = show(patches_branch, 'releaser_history.json')
        return None if raw is None else json.loads(raw)

def remove_patches(directory=None):
    # Get the current branch
    current_branch = get_current_branch(directory)
    if current_branch is None:
        error("Could not determine current branch.", exit=True)
    # Ensure the current branch is valid
    if current_branch is None:
        error("Could not determine current branch, are you in a git repo?",
              exit=True)
    # Construct the patches branch
    patches_branch = 'patches/' + current_branch
    try:
        # See if the patches branch exists
        if branch_exists(patches_branch, False, directory=directory):
            if not branch_exists(patches_branch, True, directory=directory):
                track_branches(patches_branch, directory)
        else:
            error("No patches branch (" + patches_branch + ") found, cannot "
                  "remove patches.", exit=True)