code: func Clean(b []byte) []byte {
  	if len(b) >= 3 &&
  		b[0] == bom0 &&
  		b[1] == bom1 &&
  		b[2] == bom2 {
  		return b[3:]
  	}
  	return b
  }
docs: // Clean returns b with the 3 byte BOM stripped off the front if it is present.
  // If the BOM is not present, then b is returned.