const bytes.MinRead

4 uses

	bytes (current package)
		buffer.go#L218: const MinRead = 512
		buffer.go#L227: 		i := b.grow(MinRead)

	crypto/tls
		conn.go#L836: 	c.rawInput.Grow(needs + bytes.MinRead)

	github.com/refraction-networking/utls
		conn.go#L831: 	c.rawInput.Grow(needs + bytes.MinRead)