code: public void removeCallBackUrls(ApiImplementor impl) {
  		if (impl == null) {
  			throw new IllegalArgumentException("Parameter impl must not be null.");
  		}
  		logger.debug("All callbacks removed for " + impl.getClass().getCanonicalName());
  		this.callBacks.values().removeIf(impl::equals);
  	}
docs: Removes the given implementor as a callback handler.
  
  @param impl the implementor to remove.
  @throws IllegalArgumentException if the given parameter is {@code null}.
  @since TODO add version
  @see #getCallBackUrl(ApiImplementor, String)
  @see #removeCallBackUrl(String)
  @see #removeApiImplementor(ApiImplementor)