code: func NewNewDecimalFieldDescriptor(nullable NullableColumn, metadata []byte) (
  	fd FieldDescriptor,
  	remaining []byte,
  	err error) {
  
  	if len(metadata) < 2 {
  		return nil, nil, errors.New("Metadata has too few bytes")
  	}
  
  	return &newDecimalFieldDescriptor{
  		baseFieldDescriptor: baseFieldDescriptor{
  			fieldType:  mysql_proto.FieldType_NEWDECIMAL,
  			isNullable: nullable,
  		},
  
  		precision: uint8(metadata[0]),
  		decimals:  uint8(metadata[1]),
  	}, metadata[2:], nil
  }
docs: // This returns a field descriptor for FieldType_NEWDECIMAL (i.e.,
  // Field_newdecimal)