testRemaining{5, 5},
			testRead{5, "hello", io.EOF},
			testRemaining{0, 0},
		},
	}, {
		maker: makeReg{"hello, world", 50},
		tests: []testFnc{
			testRemaining{50, 50},
			testRead{7, "hello, ", nil},
			testRemaining{43, 43},
			testRead{5, "world", nil},
			testRemaining{38, 38},
			testWriteTo{nil, 0, io.ErrUnexpectedEOF},
			testRead{1, "", io.ErrUnexpectedEOF},