title: Bokeh: Deprecated user-defined data source AND iterable values to glyph methods warning
body: <p>I have a graph with vbars in it, relevant piece of code:</p>
  
  <pre><code>fig = figure(title="Vbars", x_range=FactorRange(factors=coi[lab].tolist()))
  fig.y_range.start = 0
  fig.vbar(x="x", width=0.5, legend=False, source=source)
  </code></pre>
  
  <p>I used to have</p>
  
  <pre><code>fig.vbar(x=coi[lab], width=0.5, legend=False, source=source)
  </code></pre>
  
  <p>and wanted to get rid of the deprecation warning that stems from both supplying x and source-values. I can't instantiate a vbar-glyph without giving an x-value. How do I solve this? Can I somehow say that the x-column is contained in source? Or do I ignore the warning? </p>