code: def pwc_example(savefile="pwc_example.png"):
      params = jnp.array([1, 2, 3, 4, 5])
      time = jnp.linspace(0, 10, 1000)
      y = qml.pulse.pwc(timespan=(2, 7))(params, time)
  
      plt.plot(
          time, y, label=f"params = {params}, \n timespan = (2, 7)"
      )
      plt.legend(loc="upper left")
  
      plt.savefig(folder / savefile)
      plt.close()
  
imports: import pathlib
  import matplotlib.pyplot
  from jax import numpy
  import pennylane
label_desc: Use image node_id 2 for calling a global function with example usage: pwc_example(savefile) without return types