title: Grouped bar chart in newer versions of altair (>= 4.2.0)
body: <p>I am trying to create a grouped bar chart in altair like in the answer to this question <a href="https://stackoverflow.com/a/43800973">here</a>.</p>
  <p>The particular interesting part is the &quot;beautification:</p>
  <pre><code>chart = Chart(df).mark_bar().encode(
     column=Column('Genre', 
                   axis=Axis(axisWidth=1.0, offset=-8.0, orient='bottom'),
                   scale=Scale(padding=4.0)),
     x=X('Gender', axis=False),
     y=Y('Rating', axis=Axis(grid=False)),
     color=Color('Gender', scale=Scale(range=['#EA98D2', '#659CCA']))
  ).configure_facet_cell(
      strokeWidth=0.0,
  )
  
  chart.display()
  </code></pre>
  <p>The issue is, however, that none of the stuff in the columns (<code>alt.Column</code>) works in the current version of Altair (I am using 4.2).</p>
  <p>In particular, I am getting:</p>
  <blockquote>
  <p>SchemaValidationError: Invalid specification
  altair.vegalite.v4.schema.channels.Column, validating
  'additionalProperties' Additional properties are not allowed ('axis'
  was unexpected)</p>
  </blockquote>
  <p>Can something similar still be done?</p>