code: def fill_between(
      x=None,
      ylow=None,
      yhigh=None,
      label=None,
      color=None,
      width=None,
      dash=None,
      opacity=None,
      mode='lines+markers',
      **kargs
  ):
      
      plot = line(
          x=x,
          y=ylow,
          label=label,
          color=color,
          width=width,
          dash=dash,
          opacity=opacity,
          mode=mode,
          fill=None,
          **kargs
      )
      plot += line(
          x=x,
          y=yhigh,
          label=label,
          color=color,
          width=width,
          dash=dash,
          opacity=opacity,
          mode=mode,
          fill='tonexty',
          **kargs
      )
      return plot
docs: Fill between `ylow` and `yhigh`.
  
      Parameters
      ----------
      x : array-like, optional
      ylow : TODO, optional
      yhigh : TODO, optional
  
      Returns
      -------
      Chart