code: func (g *Grid) SetSize(numRows, numColumns, rowSize, columnSize int) *Grid {
  	g.rows = make([]int, numRows)
  	for index := range g.rows {
  		g.rows[index] = rowSize
  	}
  	g.columns = make([]int, numColumns)
  	for index := range g.columns {
  		g.columns[index] = columnSize
  	}
  	return g
  }
docs: // SetSize is a shortcut for SetRows() and SetColumns() where all row and column
  // values are set to the given size values. See SetRows() for details on sizes.