code: public Object getOneRequired(String name) throws ReferenceException {
  		Object locator = find(name);
  		if (locator == null)
  			throw new ReferenceException(null, name);
  
  		return _references.getOneRequired(locator);
  	}
docs: Gets one required dependency by its name. At least one dependency must
  present. If the dependency was found it throws a ReferenceException
  
  @param name the dependency name to locate.
  @return a dependency reference
  
  @throws ReferenceException if dependency was not found.