the plot_decision_boundary function i got from web accepts only one positional argument , however prateek bhaiya i passing three positional arguments in the function, can you please specify plot_decision_boundary function used in the video. 
the plot_decision_boundary function i got from web accepts only one positional argument , however prateek bhaiya i passing three positional arguments in the function, can you please specify plot_decision_boundary function used in the video.