code: def barplot(self, canvas, x, height, width=0.8, bottom=0, color=None, label=None, **kwargs):
          
          raise NotImplementedError("Implement all plot functions in AbstractPlottingLibrary in order to use your own plotting library")
docs: Plot vertical bar plot centered at x with height 
          and width of bars. The y level is at bottom.
          
          the kwargs are plotting library specific kwargs!
  
          :param array-like x: the center points of the bars
          :param array-like height: the height of the bars
          :param array-like width: the width of the bars
          :param array-like bottom: the start y level of the bars
          :param kwargs: kwargs for the specific library you are using.