code: @Override protected void visitCallNode(CallNode node) {
      Expression call =
          genCallCodeUtils.gen(
              node, templateAliases, translationContext, errorReporter, getExprTranslator());
      chunks.add(call);
    }
docs: Example:
  <pre>
  {call some.func data="all" /}
  {call some.func data="$boo.foo" /}
  {call some.func}
  {param key="goo" value="$moo" /}
  {/call}
  {call some.func data="$boo"}
  {param key="goo"}Blah{/param}
  {/call}
  </pre>
  might generate
  <pre>
  some.func(opt_data)
  some.func(opt_data.boo.foo)
  some.func({goo: opt_data.moo})
  some.func(soy.$$assignDefaults({goo: 'Blah'}, opt_data.boo))
  </pre>