Dotty allows private method to override public method implicitly

[molikto]

minimized code

package nio {
	abstract class Buffer {
		val isReadOnly: Boolean
	}

	abstract class ByteBuffer extends Buffer {
		private[nio] val isReadOnly: Boolean = false
	}
}

expectation

This should not compile, scalac complains with:

B.scala:8: error: weaker access privileges in overriding
val isReadOnly: Boolean (defined in class Buffer)
  override should not be private
		override private val isReadOnly: Boolean = false
                                     ^
one error found

The same thing happens with private[nio] replace with private