code: def concurrent_runs_over_time(runs, num_points=512, show=False):
      data = np.array(
          [
              (r.time_stamps["started"], r.time_stamps["finished"])
              for r in runs
          ]
      )
      ts = np.linspace(data.min(), data.max(), 512)
      n_workers = np.array(
          [((data[:, 0] <= t) * (data[:, 1] > t)).sum() for t in ts]
      )
  
      fig, ax = plt.subplots()
      ax.plot(ts, n_workers)
      ax.set_xlabel("time [s]")
      ax.set_ylabel("number of concurent runs")
  
      if show:
          plt.show()
      return (fig, ax)
  
file_path: HpBandSter/hpbandster/visualization.py
imports: import copy
  import numpy
  import scipy.stats
  import matplotlib.pyplot
  from matplotlib.widgets import CheckButtons, Button
label_desc: Use image node_id 2 for calling a global function with example usage: concurrent_runs_over_time(runs, num_points, show) and returns: fig,  ax