mock/readwritecloser.go
func NewReadWriteCloser(readErr, writeErr, closeErr error) *MockReadWriteCloser {
	return &MockReadWriteCloser{
		ReadErr:  readErr,
		WriteErr: writeErr,
		CloseErr: closeErr,
	}
}
func NewReadWriteCloser(readErr, writeErr, closeErr error) *MockReadWriteCloser {
	return &MockReadWriteCloser{
		ReadErr:  readErr,
		WriteErr: writeErr,
		CloseErr: closeErr,
	}
}
//NewReadWriteCloser - a fake readwritecloser constructor