Uses the 1. template if in the right column is some content else the 2. one.

temp.maintemplate= COA
temp.maintemplate {
  10 = COA
  10 {
    if.isTrue.numRows < styles.content.getRight
    10 = TEMPLATE
    10 {
       
      template = FILE
      template.file = fileadmin/templates/template-2column.html
    }
  }
  20 = COA
  20 {
    if.isFalse.numRows < styles.content.getRight
    10 = TEMPLATE
    10 {
       
      template = FILE
      template.file = fileadmin/templates/template.html
    }
  }
}