import matplotlib

matplotlib.use("TkAgg")

import matplotlib.pyplot as plt

fig, ax = plt.subplots(layout="constrained")
ax.plot([1, 2, 3, 4], [2, 5, 3, 6], marker="o")
ax.set_title("Interactive backend smoke test")
ax.set_xlabel("Run")
ax.set_ylabel("Value")

plt.show(block=False)
plt.pause(3)

manager = plt.get_current_fig_manager()
print(f"backend: {matplotlib.get_backend()}")
print(f"manager: {type(manager).__name__}")
print(f"figures: {plt.get_fignums()}")

plt.close("all")
print(f"closed: {plt.get_fignums()}")