How to use the pbr.git._iter_log_oneline function in pbr

def _from_git(distribution):
    option_dict = distribution.get_option_dict('pbr')
    changelog = git._iter_log_oneline()
    if changelog:
        changelog = git._iter_changelog(changelog)
    git.write_git_changelog(option_dict=option_dict, changelog=changelog)
    git.generate_authors(option_dict=option_dict)

def _from_git(distribution):
    option_dict = distribution.get_option_dict('pbr')
    changelog = git._iter_log_oneline()
    if changelog:
        changelog = git._iter_changelog(changelog)
    git.write_git_changelog(option_dict=option_dict, changelog=changelog)
    git.generate_authors(option_dict=option_dict)

def _from_git(distribution):
    option_dict = distribution.get_option_dict('pbr')
    changelog = git._iter_log_oneline()
    if changelog:
        changelog = git._iter_changelog(changelog)
    git.write_git_changelog(option_dict=option_dict, changelog=changelog)
    git.generate_authors(option_dict=option_dict)

def _get_revno_and_last_tag(git_dir):
    """Return the commit data about the most recent tag.

    We use git-describe to find this out, but if there are no
    tags then we fall back to counting commits since the beginning
    of time.
    """
    changelog = git._iter_log_oneline(git_dir=git_dir)
    row_count = 0
    for row_count, (ignored, tag_set, ignored) in enumerate(changelog):
        version_tags = set()
        semver_to_tag = dict()
        for tag in list(tag_set):
            try:
                semver = version.SemanticVersion.from_pip_string(tag)
                semver_to_tag[semver] = tag
                version_tags.add(semver)
            except Exception:
                pass
        if version_tags:
            return semver_to_tag[max(version_tags)], row_count
    return "", row_count

def _get_revno_and_last_tag(git_dir):
    """Return the commit data about the most recent tag.

    We use git-describe to find this out, but if there are no
    tags then we fall back to counting commits since the beginning
    of time.
    """
    changelog = git._iter_log_oneline(git_dir=git_dir)
    row_count = 0
    for row_count, (ignored, tag_set, ignored) in enumerate(changelog):
        version_tags = set()
        semver_to_tag = dict()
        for tag in list(tag_set):
            try:
                semver = version.SemanticVersion.from_pip_string(tag)
                semver_to_tag[semver] = tag
                version_tags.add(semver)
            except Exception:
                pass
        if version_tags:
            return semver_to_tag[max(version_tags)], row_count
    return "", row_count

def _get_revno_and_last_tag(git_dir):
    """Return the commit data about the most recent tag.

    We use git-describe to find this out, but if there are no
    tags then we fall back to counting commits since the beginning
    of time.
    """
    changelog = git._iter_log_oneline(git_dir=git_dir)
    row_count = 0
    for row_count, (ignored, tag_set, ignored) in enumerate(changelog):
        version_tags = set()
        semver_to_tag = dict()
        for tag in list(tag_set):
            try:
                semver = version.SemanticVersion.from_pip_string(tag)
                semver_to_tag[semver] = tag
                version_tags.add(semver)
            except Exception:
                pass
        if version_tags:
            return semver_to_tag[max(version_tags)], row_count
    return "", row_count

def _get_revno_and_last_tag(git_dir):
    """Return the commit data about the most recent tag.

    We use git-describe to find this out, but if there are no
    tags then we fall back to counting commits since the beginning
    of time.
    """
    changelog = git._iter_log_oneline(git_dir=git_dir)
    row_count = 0
    for row_count, (ignored, tag_set, ignored) in enumerate(changelog):
        version_tags = set()
        semver_to_tag = dict()
        for tag in list(tag_set):
            try:
                semver = version.SemanticVersion.from_pip_string(tag)
                semver_to_tag[semver] = tag
                version_tags.add(semver)
            except Exception:
                pass
        if version_tags:
            return semver_to_tag[max(version_tags)], row_count
    return "", row_count