docs: public void setAttributeStreamRef(int semantics, AttributeStreamBase stream) {
  		// int test1 = VertexDescription.getPersistence(semantics);
  		// int test2 = stream.getPersistence();
  
  		if ((stream != null)
  				&& VertexDescription.getPersistence(semantics) != stream
  						.getPersistence())// input stream has wrong persistence
  			throw new IllegalArgumentException();
  
  		// Do not check for the stream size here to allow several streams to be
  		// attached before the point count is changed.
  		addAttribute(semantics);
  		int attributeIndex = m_description.getAttributeIndex(semantics);
  		if (m_vertexAttributes == null)
  			m_vertexAttributes = new AttributeStreamBase[m_description
  					.getAttributeCount()];
  
  		m_vertexAttributes[attributeIndex] = stream;
  		notifyModified(DirtyFlags.DirtyAll);
  	}