code: def plot_time_series(meter_data, temperature_data, **kwargs):
      
      # TODO(philngo): include image in docs.
      try:
          import matplotlib.pyplot as plt
      except ImportError:  # pragma: no cover
          raise ImportError("matplotlib is required for plotting.")
  
      default_kwargs = {"figsize": (16, 4)}
      default_kwargs.update(kwargs)
      fig, ax1 = plt.subplots(**default_kwargs)
  
      ax1.plot(
          meter_data.index,
          meter_data.value,
          color="C0",
          label="Energy Use",
          drawstyle="steps-post",
      )
      ax1.set_ylabel("Energy Use")
  
      ax2 = ax1.twinx()
      ax2.plot(
          temperature_data.index,
          temperature_data,
          color="C1",
          label="Temperature",
          alpha=0.8,
      )
      ax2.set_ylabel("Temperature")
  
      fig.legend()
  
      return ax1, ax2
docs: Plot meter and temperature data in dual-axes time series.
  
      Parameters
      ----------
      meter_data : :any:`pandas.DataFrame`
          A :any:`pandas.DatetimeIndex`-indexed DataFrame of meter data with the column ``value``.
      temperature_data : :any:`pandas.Series`
          A :any:`pandas.DatetimeIndex`-indexed Series of temperature data.
      **kwargs
          Arbitrary keyword arguments to pass to
          :any:`plt.subplots <matplotlib.pyplot.subplots>`
  
      Returns
      -------
      axes : :any:`tuple` of :any:`matplotlib.axes.Axes`
          Tuple of ``(ax_meter_data, ax_temperature_data)``.