code: func (t *Tabulate) padCenter(width int, str string) string {
  	b := createBuffer()
  	padding := int(math.Ceil(float64((width - runewidth.StringWidth(str))) / 2.0))
  	b.Write(" ", padding)
  	b.Write(str, 1)
  	b.Write(" ", (width - runewidth.StringWidth(b.String())))
  
  	return b.String()
  }
docs: // Center the element in the cell