code: void changeChannelType(final ChannelType newChannelType) throws GraphConversionException {
  
  		if (!this.channelType.equals(newChannelType) && this.userDefinedChannelType) {
  			throw new GraphConversionException("Cannot overwrite user defined channel type");
  		}
  
  		this.channelType = newChannelType;
  	}
docs: Changes the channel type for this edge.
  
  @param newChannelType
  the channel type for this edge
  @throws GraphConversionException
  thrown if the new channel type violates a user setting