code: def individual_region_bars(
      small_df: pd.DataFrame, title: Union[str, Dict[str, str]] = ""
  ) -> alt.Chart:
      """Makes a stacked bar chart with runtime of each stage for individual regions.
  
      Args:
        small_df: A dataframe of regions, each of which will be shown as a bar.
        title: A title for the plot. If a dict, it should contain 'title' and/or
          'subtitle'.
  
      Returns:
        An altair chart.
      """
      columns_used = ["region", "Runtime"] + RUNTIME_COLUMNS
      d = small_df[columns_used]
      return (
          alt.Chart(d)
          .transform_fold(
              RUNTIME_COLUMNS, as_=["Stage", "runtime_by_stage"]
          )
          .mark_bar()
          .encode(
              x=alt.X("region:N", sort=None),
              y=alt.Y(
                  "runtime_by_stage:Q",
                  scale=alt.Scale(type="linear"),
                  title="Runtime (seconds)",
              ),
              fill=alt.Fill("Stage:N", sort=None),
              tooltip="Runtime:N",
          )
          .properties(title=title)
      )
  
imports: from typing import Dict, Sequence, List, Tuple, Text, Union
  from absl import app
  from absl import flags
  import altair
  import pandas
  import tensorflow
  from third_party.nucleus.io import sharded_file_utils
  from deepvariant import dashboard_utils
label_desc: Use image node_id 11 for calling a global function with example usage: individual_region_bars(small_df, title) and returns: alt