code: func (c *TableCell) SetExpansion(expansion int) *TableCell {
  	if expansion < 0 {
  		panic("Table cell expansion values may not be negative")
  	}
  	c.Expansion = expansion
  	return c
  }
docs: // SetExpansion sets the value by which the column of this cell expands if the
  // available width for the table is more than the table width (prior to applying
  // this expansion value). This is a proportional value. The amount of unused
  // horizontal space is divided into widths to be added to each column. How much
  // extra width a column receives depends on the expansion value: A value of 0
  // (the default) will not cause the column to increase in width. Other values
  // are proportional, e.g. a value of 2 will cause a column to grow by twice
  // the amount of a column with a value of 1.
  //
  // Since this value affects an entire column, the maximum over all visible cells
  // in that column is used.
  //
  // This function panics if a negative value is provided.