code: def _get_head_branch(remote_show_output):
      for line in remote_show_output.splitlines():
          match = _HEAD_BRANCH_REGEX.match(line)
          if match:
              return match.group("branch")
  
imports: import logging
  import os
  import pathlib
  import re
  import shutil
  import tempfile
  import urllib.parse
  import zipfile
  from io import BytesIO
  from mlflow import tracking
  from mlflow.entities import Param, SourceType
  from mlflow.environment_variables import MLFLOW_EXPERIMENT_ID, MLFLOW_RUN_ID, MLFLOW_TRACKING_URI
  from mlflow.exceptions import ExecutionException
  from mlflow.projects import _project_spec
  from mlflow.tracking import fluent
  from mlflow.tracking.context.default_context import _get_user
  from mlflow.utils.git_utils import get_git_commit, get_git_repo_url
  from mlflow.utils.mlflow_tags import LEGACY_MLFLOW_GIT_BRANCH_NAME, LEGACY_MLFLOW_GIT_REPO_URL, MLFLOW_GIT_BRANCH, MLFLOW_GIT_COMMIT, MLFLOW_GIT_REPO_URL, MLFLOW_PARENT_RUN_ID, MLFLOW_PROJECT_ENTRY_POINT, MLFLOW_SOURCE_NAME, MLFLOW_SOURCE_TYPE, MLFLOW_USER
  from mlflow.utils.rest_utils import augmented_raise_for_status
label_desc: Use image node_id 15 for calling a global function with example usage: _get_head_branch(remote_show_output) and returns: match