code: func NewMixedcaseAddressFromString(hexaddr string) (*MixedcaseAddress, error) {
  	if !IsHexAddress(hexaddr) {
  		return nil, fmt.Errorf("Invalid address")
  	}
  	a := FromHex(hexaddr)
  	return &MixedcaseAddress{addr: BytesToAddress(a), original: hexaddr}, nil
  }
docs: // NewMixedcaseAddressFromString is mainly meant for unit-testing