t.Logf("(%v).MarshalText() = %q", y, buf2)
		t.Fatalf("second MarshalText differs from first: %q != %q", buf, buf2)
	}
}

// checkBinaryMarshaler checks that x's MarshalText and UnmarshalText functions round trip correctly.
func checkBinaryMarshaler(t *testing.T, x encoding.BinaryMarshaler) {
	buf, err := x.MarshalBinary()
	if err != nil {
		t.Fatal(err)
	}