code: def arrow_(self, xloc, yloc, text, orientation="v", arrowstyle='->'):
  		
  		try:
  			arrow = hv.Arrow(
  				xloc,
  				yloc,
  				text,
  				orientation,
  				arrowstyle=arrowstyle)
  			return arrow
  		except Exception as e:
  			self.err(e, self.arrow_, "Can not draw arrow chart")
docs: Returns an arrow for a chart. Params: the text, xloc and yloc are
  		coordinates to position the arrow. Orientation is the way to display
  		the arrow: possible values are ``[<, ^, >, v]``. Arrow style is the
  		graphic style of the arrow: 
  		possible values: ``[-, ->, -[, -|>, <->, <|-|>]``